The Climate Prediction Center released their latest forecasts today (May 15) for June and this summer with cooler and wetter than average conditions expected in parts of Illinois.
The temperature forecast for June (Figure 1) in Illinois includes an area to the north of Interstate 74 with an increased chance of being cooler than average. This is part of a larger area of cooler conditions that runs across the northern states from the Rockies to the Appalachians. The rest of Illinois is labeled EC for equal chances of above, below, and near-average conditions – a neutral forecast.
The precipitation forecast for June (Figure 2) in Illinois includes an area south of Interstate 74 with an increased chance of above average precipitation. BTW, while I used Interstate 74 as the dividing line, the forecast obviously is not that precise in terms of geography.
The temperature forecast for June-August (traditional summer) includes northern Illinois in an area with an increased chance of below-average temperatures along with states to the north. The rest of Illinois is labeled EC for equal chances (Figure 3).
The precipitation forecast for June-August (traditional summer) has EC across Illinois and most of the Midwest (Figure 4).
If the temperature pattern for June and June-August seems familiar, here is what we have experienced in the last 30-days for Illinois and the Midwest (Figure 5). Notice the much-colder-than average temperatures across the upper Midwest (4 to 8 degrees below average). Also central Illinois has been the dividing line between the colder-than-average conditions to the north and the slightly warmer-than-average conditions to the south.