Key Points
- Nice weather for the Iowa State Fair
- Crops are looking mostly good to excellent across the state
- Expecting a fairly dry week ahead
Past Weather
Average temperatures across Iowa for the past 7 days have stayed around 4 to 8 degrees cooler than normal, with average temperatures from 63 to 70 degrees. The average daily high temperature has been 73 to 80 degrees, which is 6 to 10 degrees cooler than normal. The average daily minimum temperature has been 51 to 60 degrees, which is 2 to 8 degrees cooler than normal. Maximum temperature departures have been greater than minimum temperature departures.
Anywhere from 0.25 to 3.5 inches of rain have fallen across the state in the past week. Southern Iowa received the greatest amounts of rain. The storms delivering much of the rain this week came after several days of dry weather. Despite little rainfall in several days (until this week), cool temperatures helped reduce drought stress concerns.
Mostly dry and mild conditions make for a pleasant Iowa State Fair experience! If you want to read more about climatology during the Iowa State Fair, check out this article from the National Weather Service in Des Moines.
Crop Update
This week’s NASS crop progress shows corn conditions are 77% good to excellent, which is up 19% compared to last year. Soybean conditions are also 77% good to excellent, which is up 19% compared to last year. There is variability across the state in terms of reproductive stages of crops due to variable planting dates and replating because of the rainy spring. 69% of corn acres are at dough and 74% of soybean acres are setting pods. This week’s rainfall will help soybeans continue setting pods.
Climate Outlook
The Weather Prediction Center quantitative precipitation forecast shows little rain expected in the next 7 days, anywhere from 0-0.50 inches, so we are expecting a dryer next week across much of the state. Northern Iowa may have the best chance of getting the higher range of expected rainfall.
The 6-10 outlook (valid August 21-25) from the Climate Prediction Center shows a cool and dry signal across the eastern half of the state and a slightly warm signal along the western edge of the state. The 8–14-day outlook (valid August 23-29) shows the slight warm signal (45-50% chance) persisting and a slight dry signal throughout the state.
The 3–4-week outlook shows a warm and dry signal taking us into September. The one-month outlook for September, issued August 15, shows temperatures are expected to lean slightly above normal, and slightly drier than normal. The seasonal outlook shows a warm signal persisting and near normal precipitation.
ENSO neutral conditions are expected to continue over the next several weeks, with a La Niña watch in place. The transition to La Niña is happening slower than originally expected. La Niña has a 66% chance of developing during September to November. Once La Niña has developed, it is expected to persist into winter (74% chance) which could increase chances for a colder winter in Iowa.