Past IEM Features tagged: 100
Last Day 100+
21 Aug 2023 05:30 AMThe stage is set for a rather remarkable start to the week with extremely hot conditions forecast over the state. This is all thanks to a massive high pressure system that is actually being strengthened by the now dissipated Hurricane Hilary that hit the desert southwest as a tropical system on Sunday (hard to believe I am writing this combination). Anyway, 100+ degree daily high temperatures will be possible Monday through Thursday over the entire state. The featured map presents IEM computed dates of last 100+ degree daily high temperature with a few selected sites listed out to the side. The longest stretch below 100 shown is Charles City, which dates back to 18 August 1988. Many sites are shown dating back to 2012. Of course, 1988 and 2012 were major drought years in the state. Having drought conditions is a helpful component for such high temperatures as a drier soil warms faster than a wetter soil.
Voting:
Good: 14
Bad: 0
Tags: 100
Year of Last 100
02 Aug 2022 05:28 AMWhile previous forecasts were more bullish on portions of Iowa seeing 100+ degree highs this week, the current forecast over the next two days has slightly "cooler" temperatures forecast. The trade off is that the humidity will be on the dramatic increase with heat index values above 100 degrees instead. So it is a good time to dust off the map showing year of last 100+ degree high temperature for the NWS long term / COOP sites tracked by the IEM. The map shows some micro-climate effects as some sites have not seen 100 degrees for over 20 years while others have had much more recent occurrences. Humidity levels play a roll in this map as local increases in humidity change the energy budget and effectiveness of daytime heating in warming the lower atmosphere.
Voting:
Good: 13
Bad: 0
Tags: 100
100 Degrees after Rain
18 Jun 2021 05:24 AMThursday was a rather remarkable weather day for Iowa. Some early morning showers gave way to very hot conditions with places like Ames, Des Moines, Mason City, and Waterloo hitting 100+ degrees for a high temperature. The combination of morning measurable precipitation and afternoon 100 degree temperatures is a rare combination. For Des Moines, the unofficial IEM archives only have three instances of this happening for the site since 1936 with yesterday being the third. If one considers trace precipitation reports, there are a few more instances, but not many! The good news is that a bit cooler temperatures are in the forecast along with numerous chances of needed rainfall.
Voting:
Good: 21
Bad: 2
Tags: 100
Reaching 100 Degrees
16 Jun 2021 08:32 PMThe forecast for Thursday is a scorcher in Iowa with high temperatures expected in the triple digits for a good portion of western Iowa. Reaching the century mark is not something seen each year in Iowa and tomorrow's temperatures statewide may be the warmest seen since 2012. The featured chart presents the number of days each year with a daily high temperature of at least 100 degrees for Shenandoah (far southwestern Iowa). For this COOP site, the last 100 degree temperature appears to have been back in 2013. A simple long term trend line is fit to the plot and the influence of the dust bowl years is readily apparent. The recent lack of rainfall will certainly help boost temperatures as the sun's energy more efficiently heats the ground without having to evaporate water. Very warm air just above the surface greatly helps boosts temperatures as well.
Voting:
Good: 11
Bad: 0
Tags: 100
Year of Last 100+ Degree High
10 Jun 2017 06:29 AMThe heat arrives in force today with forecasted highs expected to be in the upper 90s and perhaps some triple digit readings will be possible over the next few days. That begs the question of when was the last 100+ daily high temperature for sites in Iowa. The featured map displays that value for the NWS COOP / long term climate sites tracked in the state by the IEM. For most of the state, it has been 4-5 years since reaching 100+ degrees. Over northern Iowa, there are some locations that haven't reported such a temperature since the 1990s!
Voting:
Good: 7
Bad: 0
Tags: 100
Cold Bias
01 Feb 2013 05:44 AMMost of the state is below zero this Friday morning. The featured chart presents an analysis of the ratio of days above 100 degrees to days below 0 degrees Fahrenheit. Locations with more days below zero have the ratio flipped to keep all values positive. Locations in white are the closest to having equal days above 100 and below 0. Nearly all of the Midwestern US has many more days below zero and there is a large gradient over Iowa. Southwestern Iowa has roughly 10 times as many days below zero than above 100, while Northeastern Iowa is around 100 times as many days! The moral of the story is that the number of days below zero dwarfs the number of days above 100 for most of the region.
Voting:
Good: 49
Bad: 12
Tags: climate 100
Sharing the Century Mark
27 Jun 2012 05:42 AMToday looks to be a very warm day with a high temperature expected to reach 100 degrees for Des Moines! If this happens, it would be the first time since 2006 for the site. The featured chart presents the frequency of other sites in the Midwest hitting 100 degrees on the same day Des Moines does. Des Moines itself shows up on the chart as 100% for illustrative purposes. The general pattern is rather clear with a southwest to northeast oriented axis of higher frequencies (more likely that locations to Des Moines southwest will also be above 100 as well). This region is a source of hot and dry air for Iowa, so it makes sense that it would also be associated with the warmest temperatures. The air mass arriving into Iowa has been destroying June and even all time record high temperatures over the plains states. Is Iowa next?
Voting:
Good: 40
Bad: 5
Tags: 100
100 degree Days
25 Jun 2012 05:41 AMThe hot weather is back with temperatures on Sunday into the lower 90s over southern Iowa and expected to warm to near 100 degrees this week. The featured chart presents the occurrences of 100 degree weather. July is certainly the favored month of the year, but having this warm of weather in late June is common as well. The bottom chart presents the number of days per year that at least one site in Iowa reported a 100 degree high temperature. The Dust Bowl era and the drought of 1988 stand out in this plot.
Voting:
Good: 35
Bad: 9
Tags: 100
Last 100 degree day
20 Jun 2012 04:58 AMThe featured chart presents the year of the last 100 degree observation for the climate sites in the state. Particularly in northeastern Iowa, it has been a number of years since the last time the thermometer reached the century mark. 1988 is certainly a popular year for this chart, which was a major drought year for the state. Our recent flirtation with these extreme temperatures has come to an end with highs expected back in the 80s for the rest of the week.
Voting:
Good: 44
Bad: 15
Tags: 100
100 degree Frequency
19 Jun 2012 05:36 AMTemperatures soared on Monday well into the 90s and may have hit 100 degrees in some very isolated locations in southwestern Iowa. Hitting 100 degrees is not that common of an event in Iowa, in particular within the recent few decades. The featured chart presents a crude analysis of the frequency of daily 100 degree temperature readings for Iowa. Southwestern Iowa is clearly the favored location along with perhaps a secondary maximum over southeastern Iowa as well. Another very warm day is expected today with highs again well into the 90s.
Voting:
Good: 38
Bad: 6
Tags: 100
5 failures to reach 100
04 Aug 2011 05:55 AMOur recent stretch of very warm weather saw some locations in the state hit the century mark. The official weather sensor for Des Moines is a the airport and the best it was able to do was 99 degrees on five different days. The featured chart presents the one minute interval temperature data for these five days. Our most recent chance on 2 August was our best one with temperatures reaching near 100 degrees early in the afternoon, but a front moved through just as the temperature was about to hit 100! The 20 July event saw temperatures hover at 99 for around three hours without hitting 100. Having five days hit 99 without hitting 100 for the year is most on record for Des Moines.
Voting:
Good: 20
Bad: 4
Tags: 100 2011
100 composite
02 Jul 2011 04:45 PMThe featured chart presents the daily temperature time series for each day the Des Moines Airport sensor was over 100 degrees. The blue lines in the plot indicate days on which rainfall was also reported. Having rainfall on 100 degree days is rather rare, which is probably an indication of having very warm air overhead that prevents thunderstorms from forming while helping to rapidly warm our temperatures.
Voting:
Good: 14
Bad: 1
Tags: 100
Getting to 100
01 Jul 2011 05:20 AMTemperatures soared on Thursday well into the 90s. Dew point temperatures were in the mid to upper 70s as well making for a miserable time outside. The featured chart presents some details on the days when the temperature has reached 100+ degrees for Des Moines. The top chart shows the morning low temperature on the days when the temperature topped 100 and the bottom chart shows the times during the afternoon that 100+ degrees were reported. Low temperatures are typically in the mid to upper 70s and the warmest temperatures occur during the mid afternoon.
Voting:
Good: 17
Bad: 3
Tags: 100
100 degrees in May
11 May 2011 08:12 AMTuesday brought an early taste of summer with high temperatures well into the 90s and dew points in the upper 60s! Record highs were set all over the state with the featured map showing reported highs from the NWS COOP network. One site in the network (Jefferson) reported 100 degrees, which is a very rare event for May. It has been 10 years since our last 100 degree temperature in May. More muggy weather is in store for the next few days before a cool down for this weekend.
Voting:
Good: 13
Bad: 2
Tags: 100
106 degrees in 18 days
17 Mar 2009 06:16 AMWith high temperatures in the 70s a few days this March, we have warmed 100+ degrees in the past 48 days from low temperatures around -30 on 16 January. The featured chart looks at the shortest period of 18 days for a 100+ degree temperature change for Ames based on data back to 1900. Let us hope our weather doesn't cool 100 degrees in the next few weeks!
Voting:
Good: 16
Bad: 10
Tags: 100
Century Mark
20 Jul 2006 06:01 AMTemperatures soared on Wednesday to 100 degrees for Des Moines and many points south and west of there. Strangely, just a few kilometers north and east temperatures were 20 degrees cooler due to clouds and thunderstorm processed air from a complex that roared thru NE Iowa on Wednesday morning.
Voting:
Good: 16
Bad: 0
Tags: 100
Almost 100!
22 Sep 2005 07:32 AMTemperatures soared yesterday afternoon to near 100 degrees in Southwest Iowa. A cold front is nearly through the state this morning and highs today will be much cooler and more seasonable. Looking forward to the weekend? Well, temperatures are forecasted to be in the 70s with chances of rain about every day.
Voting:
Good: 10
Bad: 1
Tags: 100