This will likely be a top ten coolest July on record. Using my forecast through the end of July, I have our average July temperature at 75.5. You can see the top ten list of coolest July's on record below. My forecast of 75.5 would put July 2009 at the 8th coolest on record.
Another interesting stat that the National Weather Service dug up, is that we've had 8 days this July with highs in the 70s. That's the most on record for the month of July.
ST. LOUIS (1874 - 2008)
1 74.9 7/31/1967, 7/31/1891
3 75.0 7/31/1924
4 75.2 7/31/1950
5 75.3 7/31/1971
6 75.4 7/31/1882, 7/31/1905
8 75.8 7/31/1962, 7/31/1996
10 76.0 7/31/1904
You can see there are several ties, that's why the rankings don't go in order 1,2,3,4,5 etc...
What's the cause?
We consistently saw a pattern where a strong low pressure developed in an area from the Great Lakes and Just North into Canada. This helped steer cooler air in from the North. At times, the cool air bumped in from the Northeast, but lately the pattern has cooler air streaming in on the Northwest flow that's a bit more typical of Fall.
Despite mild air moving in, the strong July sunshine makes our days warm. That's why there were plenty of hot days in the upper 80s. But the average high for July is around 90 and we're averaging a high in July 2009 near 84. In fact, there's only been 3 days at or above 90 this July.
Will August Be Hot?
There will be a handful of hot days, in fact the trend in early August looks hotter. But overall the pattern looks near to below normal for the entire month, so perhaps the latter part of August will be the cooler part of the month. But check in here on KMOV.com or on News4 for the updated 7-day as we pinpoint the periods of hot and mild temperatures.