July 2009 Saint Cloud Weather Summary

May-Like Weather Continues to Dominate Summer

Third Coldest July In St. Cloud Records

Saint Cloud Weather Summary for July 2009    

The cool weather that was persistent through much of late May and early June ended up dominating July 2009 in Saint Cloud. According to the statistics from the Saint Cloud Regional Airport, the July average temperature was 66.0°F, 3.8°F cooler than normal. That made July 2009 the third coolest July out of the 119 Julies in St. Cloud records. Only three days had an above normal temperature during the month. More impressively, there have been only 17 days with an above normal temperature in the 72 days since May 20.

The coldest period during this past July was the extended weekend of July 16-19. Temperatures were 11 to 12 degrees colder than normal all four days during this period. Five record cold temperatures were set in St. Cloud during these four days, including two record cold highs of 66 and 64 on July 16 and 17 and the record cold low of 43 on July 19. The extreme cold of this weekend was caused by a strong low pressure system that moved from the Canadian Prairie Provinces into the Great Lakes and stalled. The upper-level low pressure area kept a pocket of cold air over Minnesota through most of the weekend, keeping the clouds in and high temperatures down. Finally, on the 19th, high pressure moved right over Minnesota, allowing the low temperatures to drop to record low levels. The cool weather pattern that peaked that weekend produced ten days without a high of at least 80, resembling the normal weather of mid-May rather than mid-July.

The colder than normal weather was spread throughout the area. International Falls ended up with its coldest July on record, never reaching 80 degrees all month. International Falls also didn't have a single warmer than normal day all month.

Overall, the cold weather throughout the month was mainly due to the flow of weather systems from Canada into the Great Lakes and then on to the Northeast. In contrast, extreme heat remained persistent from south Texas to the Southwest, and actually spread up the entire West Coast, producing Seattle's first two 100-degree highs in its history and record heat in Austin and San Antonio.

The cool July combined with a slightly cooler than normal June have set up the possibility of completing one of the ten coolest summers. If August 2009 has an average temperature of only a degree cooler than normal, the summer of 2009 will end up with an average temperature of 65.2°F, tying it for tenth coldest.

Comparisons to the Last Really Cold Summer: 1992

The summer of 1992 was also the coolest in St. Cloud weather records, thanks to the suspended dust hanging in the middle atmosphere from the eruption of Mt. Pinatubo in the Phillippines. This dust led to relatively cool conditions throughout the middle latitudes over the following two years, especially during the summers. This caused one of the few breaks in the global warming trend of about 1°F seen between 1980 and 2004. More recently, St. Cloud had a cool summer in 2004, fueled by an especially cool August, that averaged near 5 degrees colder than normal and produced record early frosts just to the north of St. Cloud.

July 2009 Rainfall Still Below Normal

The dry weather that has dominated the growing season in the southeastern half of Minnesota continued during July 2009 in St. Cloud. The Saint Cloud Regional Airport July rainfall totalled 2.59 inches, three-quarters of an inch below the normal amount of 3.34 inches. For the growing season, since April 1, Saint Cloud has picked up 9.06 inches, nearly four inches below the normal growing season rainfall of 12.95 inches. The dryness was concentrated in the first two weeks of the month when only .10 inch fell between June 28 and July 13. However, heavy showers and thunderstorms on July 14 dumped 1.28 inches on St. Cloud. Other reports in the St. Cloud area showed highly variable rainfall from 1-3 inches, leading to some street flooding in St. Cloud. On that same day, 3-5 inches of rain fell from Cass to Aitkin County, including over three inches in one hour at Wieland Airport in Brainerd. These storms produced some evacuations in Staples. These storms also produced two confirmed tornadoes in west central Minnesota, a tornado in Spicer, one north of Elrosa, and several reports of funnel clouds in the St. Cloud area.

Significant rain also fell on St. Cloud on July 21-22 when 0.71 inch was recorded at the Airport, and on July 31 when .43 inch fell. The July 21-22 storms also produced widespread large hail of up to an inch in diameter in Waite Park, Little Falls, Duelm, and Little Rock Lake. The only weather-related death in the state occurred on July 21 when a 14-year-old Stillwater girl was struck by lightning.

Dry Conditions Produce Severe Drought from Twin Cities into Wisconsin

The lack of rainfall from the dry season continued to aggravate rainfall deficits concentrated in central, east central, and southeastern Minnesota. This was part of a swath of severe drought conditions, as noted by the National Drought Mitigation Center, that extended across the northern half of Wisconsin and parts of Upper Michigan. In fact, the immediate St. Cloud area is the one relatively wet hole in the very dry conditions extending from the Minnesota River Valley into the Twin Cities. Growing season rainfall deficits exceed five inches from the Upper Minnesota River Valley through western Stearns County, Willmar, Litchfield, and Hutchinson. Deficits are 6-8 inches from Litchfield through the Twin Cities and into Washington County. Some of these areas have a rainfall deficit of over a foot of rain, including the dry portion of last summer and fall. Streamflows in the Lower Minnesota River Valley and parts of the St. Croix are extremely low, in the lowest 10% of flows on record in some areas. The only factor that has mitigated the rainfall shortage is the cool weather, which reduces the amount of evaporation.

However, the cool temperatures have put crop development a bit behind schedule. Wheat and barley development have been especially slow. This doesn't necessarily mean a bad crop, but it requires an extended growing season by 2-4 weeks to keep crop development normal. On the other hand, corn development has the potential of being very good in Minnesota and throughout the central US.

Cool Weather Keeps Severe Weather Season Slow

Despite the mid-July severe weather, Minnesota is having a relatively quiet severe weather season. Only nine tornadoes have been observed in central and southern Minnesota through the end of July, far below the normal annual number of 26. The cool and dry weather has been a major factor in keeping the severe weather down in Minnesota. The most recent year with such few tornadoes was 1992, when only 12 tornadoes occurred.

Likely a Cool Start to August

The latest long range forecasts continue to show more of the same: a blocking high pressure area over the West Coast into south Texas, which will keep the heat on in the Interior West to Texas, and a low pressure system over Hudson Bay that will keep the steering winds blowing from north central Canada into Minnesota, the Great Lakes, eastern Canada, and the Northeast. This will continue the succession of cooler weather systems into St. Cloud through the first 7-10 days of August.

    July 2009 Statistics