Past IEM Features tagged: windchill
Winter to Date Wind Chill Hours
30 Jan 2024 05:30 AMThe daily feature one week ago presented a time series of recent wind chill advisories and warnings for Ames. A quick warm up on Monday to 49°F with ample sunshine and this period feels like a long while ago. The featured chart today looks into the accumulated hours at or below a given wind chill threshold. The plotted values consider all wind chill temperatures, even when the wind is calm. The season to date values are plotted this year (blue line) and all years on record for Ames since 1997. A simple mean and 25th and 75th percentile values are plotted as well. This season has seen above average number of hours at the extreme cold thresholds, but well below average at the more mild thresholds. Such has been the case this winter with not much for cold outside of the very cold few weeks earlier this month.
Voting:
Good: 9
Bad: 0
Tags: windchill
January Min Wind Chill
02 Feb 2023 05:30 AMOutside of the cold experienced to end the month, January was not all that bad for temperatures in Iowa. One measure of how bad it was is shown by the featured chart of yearly minimum wind chill temperatures for Des Moines during January. The 2023 value comes in near the 95th percentile. Approximately 19 out of every 20 previous Januaries had a colder value. It is kind of interesting to note two of the years failed to even reach a sub zero Fahrenheit value! Temperatures did warm nicely for the first day of February for most of the state, but a reinforcing shot of colder air arrives on Thursday.
Voting:
Good: 9
Bad: 0
Tags: jan windchill
Wind Chill Advisory 1,2,3
31 Jan 2023 05:30 AMWhen the National Weather Service issues alerts, they are usually sequentially numbered starting at one on 1 January. Our ongoing stretch of bitter cold wind chills has necessitated the issuance of a number of Wind Chill Advisories. The featured chart presents the combination of recent winter headlines valid for Mason City along with hourly wind chill observations. The past three days have seen three such advisories with the ongoing one scheduled to end later this morning.
Voting:
Good: 12
Bad: 2
Tags: windchill
Cedar Rapids Wind Chill Warning
26 Jan 2022 05:34 AMWind chill temperatures this Wednesday morning are brutal with air temperatures well below zero and a brisk NW wind pushing values even further below zero over Iowa. The NWS has a Wind Chill Warning in effect primarily over northeastern Iowa covering locations like Cedar Rapids. The featured chart presents the frequency of having either a Wind Chill Advisory or Warning active at a given wind chill temperature since early 2006 for Cedar Rapids. The chart nicely delineates the thresholds at which these warning/advisory events are issued at. Values below -20 are mostly covered by the advisory with values below -30 and particularly below -35/-40 covered by the warning. One can hope this is the worst that this winter will have to offer, but there is still plenty more time to go!
Voting:
Good: 9
Bad: 0
Tags: windchill
Hours of Wind Chill
06 Jan 2022 09:25 PMThe thought of setting an all-time record high temperature during the month of December, just last month, is a bit of a far off memory given the plunge into the deep freeze this week. Wind chill temperatures today were well below 0F. The featured chart presents the number of accumulated hours with a wind chill temperature at or below the given threshold for Ames by season for the season to date period. The blue line shows the 2021-2022 accumulated total with each previous year on record plotted in tan along with selected percentile values. The accumulation this year has been below average for most thresholds. We will have another chilly today on Friday before a bit warmer weather moves in for the weekend and next week.
Voting:
Good: 15
Bad: 1
Tags: windchill
Cold Wind Chills
26 Feb 2021 05:34 AMThe featured chart presents an accounting of the amount of time spent below a given wind chill temperature threshold based on hourly data for Des Moines. The chart only considers the cases whereby wind speeds were strong enough to cause a decreased wind chill temperature. The winter to date season this year is compared with a simple average from previous years. The prolonged cold spell earlier in February really racked up the totals, but not for the extreme cold values below -32 degrees. It is also curious to see the below average totals for thresholds closer to zero. The brutal cold for this winter season has been intense, but on the slightly brief than average side so far.
Voting:
Good: 14
Bad: 2
Tags: windchill
Wind Chill Headlines
16 Jan 2020 05:34 AMA brisk wind ushered in much colder air into the state overnight, dropping wind chill temperatures below -20 degrees Fahrenheit for some locations. The National Weather Service issued a Wind Chill Advisory to highlight the threat for locations like Mason City. The featured chart presents the frequency of having either a wind chill advisory or warning active at a given wind chill temperature for the site. The major caveat here is that these alerts have a duration requirement, so it is not a simple trigger once a site dips below the advisory threshold. Values can also fluctuate above and below an alert threshold over the duration of the alert. There is more cold like this in the forecast along with a major winter storm forecast for Friday into Saturday!
Voting:
Good: 9
Bad: 0
Abstain: 1
Tags: windchill
Just getting started on cold wind chills
15 Jan 2020 08:53 AMThe featured chart presents the accumulated amount of time each winter season that the wind chill temperature was below a given threshold. For this plot, even when the wind is calm the resulting wind chill is included in the plot. The total so far for the 2020 season is shown along with a simple average and each previous winter season for Ames. The point is to show that we are just getting started for the season accumulating such cold readings. The forecast for the next week or so will start finally accumulating cold readings for the season.
Voting:
Good: 7
Bad: 0
Tags: windchill
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Generate This Chart on Website
Updated map shows Charles City now the coldest at -59.
Generational Cold Wind Chills
30 Jan 2019 06:17 AMThe ongoing extreme cold over Iowa has much of the state shutdown for this Wednesday. The forecast of generational cold wind chills came to fruition. The featured map displays the lowest wind chill temperature for today based on hourly observations from the airport weather stations in the state. The lowest shown is -58 for Estherville, which is coldest value ever reported from the site with data back to 1987. At this point, it appears we will not break the all-time record coldest wind chill in Iowa of -64 set back on Christmas Eve 1983 at Waterloo.
Voting:
Good: 16
Bad: 0
Tags: windchill 2019
University Closure
29 Jan 2019 05:33 AMIt is remarkable to see all three state of Iowa universities closing this evening until Thursday noon due to dangerous wind chills. The featured chart depicts the forecast combination of air temperature, wind chill and wind speed for Ames. This chart bottoms out the wind chill temperature near negative 50 degrees and shows a high temperature of just -10 on Wednesday! Amazingly after this stretch of cold, much warmer weather is expected with the air temperature around 90 degrees warmer than the minimum wind chill plotted on this chart (-50 to 40).
Voting:
Good: 17
Bad: 1
Tags: windchill 2019
Accum Wind Chill Time
26 Dec 2017 07:06 AMThe coldest air of the season is currently impacting the state with some bitterly cold wind chills prompting the issuance of Wind Chill Advisories. The featured chart looks at the accumulated amount of time that Des Moines has a wind chill temperature at or below the given temperature. This plot only considers cases when the wind was blowing strong enough to be measured. The totals this far for 2017 are well below average, but of course, we are just getting started for the season! Some even colder air is expected later this week.
Voting:
Good: 6
Bad: 0
Tags: windchill
Coldest Wind Chill
24 Apr 2017 05:34 AMWhile the cold periods this past winter season have been limited, the coldest wind chill reported for Des Moines was as cold as we have seen this past decade at about -30. Thankfully, there is no chance of having a colder temperature this spring. The top panel displays an accumulated histogram for the coldest temperature. The -30F this year is at about 70th percentile, so roughly seven out of ten years have had a colder minimum wind chill temperature.
Voting:
Good: 6
Bad: 2
Tags: windchill
Limited Cold Wind Chills
17 Feb 2017 05:37 AMVery cold weather this winter has been difficult to come by as shown by the featured chart presenting the number of hours with wind chill at or below a given temperature for Des Moines. The red dots are this winter season and the blue dots are a simple average since 1973. The totals for this year are 50% of and often lower than average. The next seven days will feel more like spring than winter, so no further accumulation on this chart is expected until next weekend.
Voting:
Good: 14
Bad: 0
Tags: windchill
Wind Chill Advisories
15 Dec 2016 05:35 AMA Wind Chill Advisory is in effect for much of northern Iowa this morning as cold air and brisk winds are coming to push feels like temperatures well below zero. The featured map displays the yearly frequency of Wind Chill Advisories by county in the state. The highest frequencies are shown over the flat areas of north central Iowa with Fremont County in far southwestern Iowa indicated as the lowest. Why does such a gradient exist over the state? The coldest air masses arrive in Iowa from the NW and the flat areas over north central Iowa are the windiest in the state, so this area is favored for the coldest wind chill values. Also as you go south and when winds are from the NW, these tend to be more chinook influenced, which means the air is warmer due to down-sloping from the Rocky Mountains.
Voting:
Good: 14
Bad: 1
Tags: windchill
Wind Chill Map
09 Dec 2016 05:34 AMThe coldest wind chills of the season thus far impacted Iowa on Thursday with wind chill values near or below zero for most of the state. How cold can the wind chill values yet? The featured map displays the 99.8th percentile coldest wind chill temperature based on long term hourly weather reports. This percentile level would approximately represent the level of the 12th coldest hour of the season. Restating, the plotted level indicates the temperature at which we'd expect to see 12 hours of wind chill at that level or colder. So for Iowa, we're in the -30 to -40 range. The map also helps equate wind chill temperatures over the country. So such weather in Iowa compares with about a wind chill of 20 above in Northern Florida :)
Voting:
Good: 17
Bad: 2
Tags: windchill
Wind Chill Time
10 Feb 2016 05:35 AMThe recent snow and blowing snow combined with cold air to produce sub zero degree Fahrenheit wind chill readings for the past two days. How common are such cold wind chills for the winter season? The featured chart displays the number of hours per season that the wind chill temperature is at or below a given threshold. The number of hours is expressed in units of 24 hour days for easier comprehension. The 25th and 75th percentiles are shown along with the average and maximum values. The accumulation so far this 2016 is plotted as well. Of course, we have plenty of winter season to go and the chart indicates that we have only seen about half of the time we'd expect to see such bitterly cold wind chills.
Voting:
Good: 54
Bad: 40
Abstain: 45
Tags: windchill
Wind Chill Alerts
18 Feb 2015 05:42 AMThe NWS has a Wind Chill Advisory issued for today as another round of very cold air arrives in the state today. The featured chart displays computed wind chill values for Ames along with periods with either a wind chill advisory or wind chill warning active. These alerts are not always issued when temperatures get very cold along with very light winds as what happened a few weeks back. High temperatures today will struggle with some locations not exceeding the single digits.
Voting:
Good: 16
Bad: 8
Abstain: 3
Tags: windchill
Wind Chill Warning
07 Jan 2015 05:39 AMAir temperatures have dropped and winds have increased this morning. The combination of both have conspired to create dangerous wind chills. Many schools have cancelled classes today due to the wind chill. The NWS has issued a Wind Chill Warning for today until noon for much of Iowa. The featured chart presents the frequency of when during the day a wind chill warning is active for Story County (Ames). Rewording, when a wind chill warning is active, what is the frequency during the day that the warning was active. The afternoon hours are the least favored time, which makes sense as it will likely be the warmest portion of the day. Products like these are issued on a 3 hour increment of time, which is why there is a rapid cut off at noon.
Voting:
Good: 20
Bad: 7
Abstain: 4
Tags: windchill
Minimum Wind Chill by Year
30 Dec 2014 07:25 AMBelow zero wind chill readings are common over Iowa this morning. The featured chart presents the frequency of season minimum wind chill reading (top chart) and the yearly minimum (bottom chart). Every year that we have data for has seen a sub zero wind chill with at least a sub -10 degrees Fahrenheit common each year.
Voting:
Good: 9
Bad: 4
Abstain: 4
Tags: windchill
Wind Chill Advisories/Warnings
06 Feb 2014 06:06 AMThe entire state is under a wind chill advisory this morning with current readings in -30 to -20 range. The featured chart presents a time series of calculated wind chill values for Waterloo since 20 Dec 2013. The shaded regions are the wind chill advisories and warnings issued by the National Weather Service. There have been plenty of these events so far this winter season and only a modest break between then during the second week of January. A brief warm-up back to values closer to freezing is expected tomorrow before the next round of snow and cold pushes us back into deep freeze weather.
Voting:
Good: 35
Bad: 8
Abstain: 4
Tags: windchill
Comparing with 1983
09 Jan 2014 05:44 AMThe recent stretch of cold weather had a minimum wind chill of -45 degrees for Waterloo. The featured chart presents time series of wind chill using the current day equation for the ten coldest events for Waterloo. The most recent event is plotted as well for comparison. The coldest wind chill was associated with the epic Christmas Eve 1983 and is shown by the blue line. While temperatures were below -20 for two solid days this year, for the 1983 event they were close to or below -40 for three straight days! After another cold start this morning, temperatures will be improving with highs expected just above freezing on Friday for Waterloo.
Voting:
Good: 26
Bad: 1
Abstain: 2
Tags: waterloo windchill 1983
Very cold wind chills
07 Jan 2014 05:44 AMThe featured map presents an IEM computed analysis of minimum calculated wind chill up until 12 AM 7 January. The lowest reading among the airport stations in Iowa was -51 from Oelwein. Most of the state bottomed out in the -35 to -45 range. Some even colder readings were found in Wisconsin, Minnesota, and North Dakota. A few isolated locations were able to reach -60! Temperatures will be on the rebound today with highs above freezing expected by later in the week!
Voting:
Good: 27
Bad: 4
Abstain: 5
Tags: 2014 windchill
Wind Chill Frequencies
06 Jan 2014 05:39 AMMuch of the Midwest is in the firm grasp of winter this Monday morning with extreme cold and gusty winds making for life threatening conditions. Wind chill readings this morning are some of the coldest in many years. The featured chart presents the percentage of winter seasons that experience a given threshold wind chill reading for at least one hour that winter. Almost every year gets down to -20 with about half reaching -35. The extreme temperatures reached today will be in the 10% or lower frequencies, which means this is once in a decade or two weather.
Voting:
Good: 61
Bad: 5
Abstain: 3
Tags: windchill
Below 0 Windchills
20 Feb 2013 05:41 AMTuesday was a brisk reminder of the winter season we are still in with wind chill values below zero for most of the state. The featured chart displays the daily frequency of having at least one wind chill reading below zero. Three selected sites are shown for comparison. The frequencies peak out around 60% for most of January and the first few weeks of February. We are on the downward slope of this chart as we creep closer to springtime.
Voting:
Good: 32
Bad: 6
Tags: windchill
Wind Chill Hours
25 Jan 2013 05:41 AMThe featured map presents an analysis of the average number of hours per year that the wind chill reading is below zero. The total number of hours is presented in units of 24 hour day periods for easier comprehension. While there are some local poor data effects, the north to south pattern is clear with the nation's ice box around 50 days and the south under 1 day. The gradient over Iowa is fairly strong with northern Iowa near 30 days and southern Iowa around 10. The past week has seen the coldest wind chills over north central Iowa, which makes the preferred region in the state for the most frequent sub zero wind chills.
Voting:
Good: 67
Bad: 13
Tags: windchill
Plenty of cold for all
04 Feb 2011 05:52 AMThe featured map presents an IEM analysis of the lowest wind chill temperature reported so far this month. In the wake of our most recent blizzard storm system, very cold air has frequented a good portion of the country pushing wind chill values below zero for places like Texas. Some of the coldest wind chills ever recorded were present for some locations in Oklahoma and Kansas. Values below -50 F were observed as well. The good news is that our immediate future has a slight warm up with temperatures close to freezing!
Voting:
Good: 28
Bad: 5
Tags: windchill
The wind and the cold
21 Jan 2011 07:04 AMVery cold temperatures and a bit of wind have conspired over night to bring bitterly cold wind chills to Iowa this Friday. The featured chart presents the reported wind chill against the air temperature during hours which the wind speed was measurable. Histograms of each are presented at the side and top. -20°F is roughly an observed threshold of wind chill where frequencies start declining at colder temperatures. Of course, the most extreme values are even more rare and often do not happen every year.
Voting:
Good: 44
Bad: 27
Tags: windchill winter
Frequency of cold wind chills
12 Jan 2011 05:52 AMA bitter north west wind is blowing this morning and with temperatures in the single digits, wind chills are well into the negative range. The featured chart presents the number of hours per winter season that wind chills values below -20F were reported at the Des Moines and Sioux Falls airport. During every year, except one, Sioux Falls has had more hours below -20 than Des Moines. The chart does show that these bitter cold temperatures have been less common in the past ten years than the previous 30. The brutal winters of 1977 and 1978 show up prominently on the chart.
Voting:
Good: 15
Bad: 4
Tags: windchill
Sub Zero Wind Chills
03 Feb 2009 06:13 AMWind Chill values are again running well below zero this morning with a good portion of the state under a wind chill advisory. How often are wind chill values this cold? The featured table displays the number of hours exceeding certain temperature thresholds. This winter (shown as 2008) has seen 15 hours of sub -30F, which is at the simple historical average of 15 based on data back to 1973. The brutal winters of 1978 and 1983 are shown as well for comparison.
Voting:
Good: 20
Bad: 6
Tags: windchill winter