A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the first Monday of each month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
distributed: August 3, 2012
What happened in July 2012:
- July 2012 monthly precipitation totals were very low across much of Minnesota, especially in southwestern counties. July rainfall totals were well under one inch in the driest areas. In many Minnesota communities, monthly rainfall amounts fell short of the historical average by one and one-half to three inches. The overall dry pattern was dissected by narrow stripes of heavier precipitation. Confined areas from Warroad to Grand Portage, and from Moorhead to Aitkin, received above-average July rainfall.
- Monthly mean temperatures for July 2012 were four to seven degrees above average over most of Minnesota. Preliminary data indicate that July 2012 was the second warmest month (any month) in the modern climate record. It was Minnesota's tenth consecutive month of above-normal temperatures. Extreme temperature values for July ranged from a high of 103 degrees F at Gaylord (Sibley County) and Minnesota City (Winona County) on the 6th, to a low of 42 degrees F at Agassiz National Wildlife Refuge (Marshall County) on the 27th.
[see: Hot July in Twin Cities]
Where we stand now:
- The U. S. Drought Monitor, released on July 31 places many northwestern and southwestern Minnesota counties, and portions of some southeastern Minnesota counties, in the Severe Drought category. Other northwest and southern Minnesota counties are described as undergoing Moderate Drought. In total, approximately 50 percent of Minnesota is considered to be in the Abnormally Dry category or worse. The drought situation in northwest Minnesota is the result of a dry autumn, a snow-sparse winter, and a dry growing season. The moisture deficits in southern Minnesota developed rapidly due to very hot and very dry conditions in late June and throughout July. The U. S. Drought Monitor index is a blend of science and subjectivity where drought categories (Moderate, Severe, etc) are based on several indicators.
- The U.S. Geological Survey and Minnesota DNR report that stream discharge values are very low at some northwest Minnesota reporting locations. Stream flow values rank below the 10th percentile for this time of year in some of these watersheds. Stream discharge values are also quite low at many locations in southern Minnesota counties. Stream flows are high in some east central and northeastern Minnesota basins. Stream discharge values in these watersheds rank above the 75th percentile when compared with historical data for the date.
- Water levels on many Minnesota lakes are falling in response to the dry, hot weather. Lake Superior water level is similar to the 2011 level at this time of year and somewhat below the long-term average for the date.
- In their July 29 report, the Minnesota Agricultural Statistics Service reported that topsoil moisture was 18% Very Short, 32% Short, 47% Adequate, and 3% Surplus across Minnesota. This represents a significant degradation in conditions when compared with an early-June soil moisture survey reporting only 5% of the landscape Short or Very Short. However, 55 to 60 percent of Minnesota's corn and soybean crop is said to be in good or excellent condition. This is a significantly higher percentage of favorable conditions than those reported by other Corn Belt states.
- The potential for wildfires is currently rated by DNR Forestry as Moderate in northwest Minnesota and in the southern one-third of the state. The wildfire potential is considered Low elsewhere in Minnesota.
Contributions of information and suggestions are welcome!