July 17th-20th Significant heat wave report. many mid 90 degree highs with record setting humidity. Worst heat wave in 20 years.

U.S Heat index readings on July 19th 2011 Image from Weather.com

A significant heat wave impacted not just the local area, but the entire country with sweltering heat and humidity. Heat warnings or advisories were issued for the entire Upper Midwest in advance of the heat wave, and covered much of the Central U.S at least 10 states were put under some type of warning for heat from Oklahoma north to the Canadian border.

A outdoor prickly pear cactus which appropriately bloomed during the hot weather.

More locally this was the worst heat wave in 20 years. Most days during the start of this week had highs in the mid 90s, causing many issues for everyone. Most people were effected not only by the storms this system produced, but the heat made most people put off outdoor actives. I stopped mowing lawn just staying indoors with the certains shut to keep out the sun and the air on to keep cool. It really wasn't the heat with this heat wave, it was much more the oppressive humidity that we were locked under for days. Record setting dewpoints that read as high as 82.F put heat index values well over 100.F each day, some days heat index values were as high as 113 to 117 degrees. The setting of the sun did not provide any relief either. Once the temp rose into the mid 70s on Sunday Night, it did not cool off below there until the end wave ended. Night time lows were way up in the mid to upper 70s, with extremely humid conditions, this made heat index never fall out of the 80s at many locations. Then when the next morning arrived it quickly hot too hot to be outside by 10am most mornings my temp was already in the mid 80s!

Very Humid evening July 17th 2011

As stated above recording setting dewpoints were reached here in Western Wisconsin. The highest area dewpoint I saw from our area was 82.F from Osceola, Which is more typical of tropical jungles then it is Wisconsin, It is safe to say that dewpoints that high are certainly unheard of in our region. The picture above was taken during one of the humid evenings when the dewpoints were in the 80s, the air which was hazy from humidity it could be mistaken for fog! I also had to continually wipe off the camera lens when I took this picture because it kept fogging up, the camera coming from our cool house outside caused instant fog on the lens!

Numbers at my station

My station did break some 3 year records. Monday night the 18th, I has the warmest low temperature I've ever recorded. The low was 79.F. I also had the highest heat index value, which was 117.F. This was also a the first time I recorded 90s in a 4 day stretch. Making this year the most with mid 95 degrees highs I've ever record for one year. The highs and lows were as follows from the 17th through the 20th. 17th, 95/73. 18th, 96/79. 19th, 92/73. 20th, 95.F/73. Besides in my 3 year records I asked locals around the area how long it's been that hot, and most said it's been a very long time. My dad who even said it has never been that hot since he moved to Wisconsin more then 20 years ago. He actually found it to be ridiculously humid since he move here from Alabama to escape hot and humid conditions! Many people, as well as me were glad when a cold front that went through on Friday finally brought much needed relief from the area.

High temperatures reported on the 20th of July

Above is the are the highest temperatures that were reported when our heat wave peaked on Wednesday July 20th Dew points were in the low 80s during this day, so while temperatures were in the mid 90s, heat index values were well above 100.F. The highest station in the area was Knapp and Glenwood City at 97.F and the coolest was Cumberland at 90.F Stations with a * sign are official NWS sites.