July 2006 Heat and Summer Dry Spell

Hottest July Since 1936

The late July heat wave pushed July 2006 to the 8th hottest July in Saint Cloud history (average temperature of 75.1°F), beating July 1988 (11th hottest) by a half of a degree. July 2006 was the hottest July in Saint Cloud since 1936 (the hottest July in Saint Cloud history).

Duluth did set a new record for the hottest July as the heat came with persistent west winds, keeping the cooler air over Lake Superior off shore for much of the month.

Longest Saint Cloud Heat Wave In 32 Years

Saint Cloud's second long streak of consecutive 90-degree highs has reached 9 days through Monday, July 31. This is the longest heat wave (3+ days with a high of at least 90) since the heat wave of mid-July 1964. The longest heat wave in Saint Cloud history remains the 14-day streak in 1936, the hottest period in Saint Cloud records with 9 standing record highs and 9 of the 14 days with a high of at least 100 degrees.

Thus far, 2006 has had two long July heat waves. The last time there were two 5-day heat waves mostly in July was in 1966. This has only been done before in June 1910, July 1931, June 1933, and June 1936. 1995 had two long heat waves but they were in different months. The most 5-day heat waves in a summer are three, set in 1931, 1936, and 1964.

The shorter heat wave in July 1995 was accompanied by record-high dew points in the high 70's and lower 80's. This 1995 heat wave caused over 600 deaths in Chicago and Milwaukee, plus the deaths of millions of livestock from Iowa, southern Minnesota, into Illinois and Indiana.

July 90+ degree highs

The two long July 2006 heat waves have produced 15 days with a high of at least 90 degrees. This is the most number of 90 degree highs since 1936.

Annual 90+ degree highs

While the number of 90+ degree highs has already climbed well beyond the normal annual total of 11.4 days, the 2006 total is well short of the record of 36 days, set in 1936, or the 1988 total of 33 days.

Back to 100 Degrees for the First Time in 16 Years

On July 31, the Saint Cloud Airport high was 101°F, the first time that Saint Cloud had broken 100°F since July 3, 1990. However, this still fell short of the July 31 record high of 102°F, set in 1988. Since 1950, Saint Cloud has hit 100 degrees only on 9 days, 7 of which were in 1988. Also, the Saint Cloud history of 100 degree days shows that there have 58 days since 1893 hitting 100.

75°F Low More Rare than 100°F Highs

On July 30, the low temperature in Saint Cloud was only 76°F. To get a low temperature that warm, we need a very humid air mass and a stiff breeze overnight. This marks only the 52nd day in Saint Cloud history in which the low never dropped below 75°F. That's fewer days than Saint Cloud has hit 100°F (59 days). In contrast to the 100°F highs, which have been rare since 1950, this marks the 15th day since 1950 with a low temperature above 75°F, 7 of which have come since 1996. This would be supportive of the idea that summers have been more humid recently, although they haven't been that warm until the past couple of years.

There have been 4 days so far this summer with a low of at least 70°F. The normal total for the year is 3 days.

Dry Spell Ranks as Moderate to Severe Drought

The dry weather since late spring is the main reason for parched lawns, low streamflow, and struggliing crops. Between May 15 and July 30, the Saint Cloud rainfall totalled only 3.92 inches, more than five and a half inches below normal. However, a line of slow-moving heavy thunderstorms stalled along a Morris-Glenwood-Little Falls/St. Cloud-Cambridge line on the evening of July 31. Saint Cloud picked up 1.01 inches of rain (0.97 inch on July 31) with Little Falls getting 1.71 inches (1.59 inches in one hour), easing the dry conditions locally somewhat. However, Saint Cloud is still more than four and three-quarter inches behind on rainfall through the end of July.

The Minnesota State Climatology Office's update on the two-month long dry period also shows that southeastern Stearns County, plus most of Sherburne and Wright Counties, are in the driest 5 percent of years for this period. The most extreme conditions also exist in the northwestern part of the state and most of Minnesota are in the red and brown colors, meaning that this year is in the driest 20% of years.

The latest US Drought Monitor from the National Drought Mitigation Center (updated on Thursdays) shows that a stripe from northwestern Minnesota to Crow Wing County (Brainerd area) and east to the Wisconsin border ranks as an extreme drought with most of the rest of the state ranked in the moderate category.

Conditions don't look to be quite as severe on in the growing season (April 1 - current) rainfall map from the Minnesota State Climatology Office. The reason is that rainfall was actually more than 2 inches above normal through May 14, mainly due to the heavy rain seen from April 28 through May 2 when more than 3 inches of rain fell.

You can find more dry spell resources on the Minnesota State Climatology Office's 2006 Dry Spell Resources Page.

The last significant dry spell in Minnesota was a 10-month dry period from July 15, 2003 through the rest of the 2003 growing season and continuing through mid-May 2004 after the ground thawed. The rainfall deficit from mid-summer 2003 through April 2004 in Saint Cloud reached more than six and three-quarters inches until the rains came.

During the summer of 2005, we also went through a 2 1/2 month dry spell that caused some problems. However, it was short-lived enough so that heavy rains in August through October were able to prolong the growing season.

Although the 2003 10-month dry period could not compare to Minnesota's last major drought during 1986-1989, the period was intense enough to cause much of the state to be classified in the moderate to severe drought categories.