The Heat Wave of 2012 finally came to end this past Saturday here in the Upper Midwest. It was brought several days in the 90s, and a few places in Western Wisconsin topped out at or above 100 degrees a couple of days. It made for the hottest Fourth of July in Eau Claire since 1999. The heat wave not only impacted the Midwest, but across the country records were shattered. Even all-time high temperature records were broken that go back all the way to the Dust Bowl years of the 1930s. St. Louis, MO spent ten days straight at 100 degrees or higher. That’s the second most in recorded history. This year’s heat wave missed out on the number one spot, which was a thirteen day stretch of 100s back in 1936. That year brought a July heat wave like non-other to the entire nation.
But let’s take a look back at this heat wave in 2012. It all got started towards the end of June on the 27th. The high in Eau Claire climbed to 91 degrees as a ridge of high pressure would build into the area. That ridge of high pressure would dominate much of the country for the next several days. Starting on June 29th, Eau Claire began an eight day stretch of highs in the 90s, which came to an end this past Friday. That makes those eight days the fourth longest stretch of consecutive 90s in recorded history for Eau Claire. The longest stretch was eleven days back in July of 1964. Here’s a table showing the high temperatures during this heat wave in Eau Claire.
Date: High Temperature:
June 29 90
June 30 90
July 1 92
July 2 99 Record
July 3 92
July 4 98 Record
July 5 94
July 6 99
We never could quite break 100 degrees. These temperatures are still well above normal though. Below is a look at the departure from normal for high temperatures for the first six days of July. The Chippewa Valley was running a good 12-14 degrees above normal compared to normal for these days. Check out the Coulee Region though. Average high temperatures were an impressive 14 to 18 degrees above normal!
The nights were also quite warm as well running 9 to 12 degrees above normal as you can see by the image below. Both are from the National Weather Service in the Twin Cities.
The combination of that heat along with dew points that hovered in the upper 60s to mid-70s last week made for heat index values soaring between 100 to 110 degrees. It was oppressive! Excessive Heat Warnings were out for most of the SkyWarn13 Viewing area along with a good chunk of the nation from Tuesday until Friday. Unfortunately, several people lost their lives due to the excessive heat.
The heat wave last week was far worse in the La Crosse area as I kind of alluded to above. Check out this chart from the National Weather Service in La Crosse. Twice during the week La Crosse topped out at 103° for a high temperature. One of those days was the fourth of July and the other was July 6th. Both days tied records.
The reason the heat was worse for the La Crosse area was because it missed out on some complexes of rain and storms that moved through areas further north like Eau Claire. Also, the Coulee Region is drier in general than other portions of Western Wisconsin. The area is currently “abnormally dry” according the U.S. Drought Monitor. Those dry conditions helped La Crosse get hotter. A very persistent ridge was why the heat wave lasted so long for all of us here in Western Wisconsin. Thankfully, the heat wave has broken for us. Highs this week will be much more seasonable and dew points will be far more tolerable. The heat wave of 2012 will be memorable across the country. I just hope there’s no round 2!