FirstWarn Weather

First Warn Forecast
Wednesday, June 3, 2026

Another beautiful early June day is on tap across Missouri and Illinois as high pressure remains firmly in control of our weather pattern. Temperatures started the day on a cool note, with many locations falling into the middle and upper 50s and a few of the typically cooler spots dipping into the lower 50s. While the morning may feel more like spring than summer, abundant sunshine and a high June sun angle will quickly warm temperatures into the lower 80s this afternoon.

Low humidity levels will continue to make conditions feel very comfortable through the day. Light winds, plenty of sunshine, and dry air will provide excellent weather for outdoor activities, yard work, or simply enjoying some time outside. Tonight will be another pleasant night with mostly clear skies and temperatures dropping back into the mid-50s to around 60 degrees.

The weather remains quiet on Thursday as the area of high pressure gradually shifts toward the East Coast. As this occurs, winds will begin turning more southerly across the Mid-Mississippi Valley. That change in wind direction will allow temperatures to warm a few more degrees, with afternoon highs climbing into the middle 80s. Humidity levels will begin increasing slightly, but overall conditions will still remain quite comfortable and dry.

As we move into Friday and the upcoming weekend, the weather pattern begins to transition toward a more typical early summer setup. Warmer and more humid air will continue flowing northward into Missouri and Illinois while a series of disturbances approach from the Plains. This will bring the return of chances for showers and thunderstorms beginning Friday afternoon and Friday night. At this time, it appears that any storms moving into the region Friday evening may be weakening as they arrive, though a few stronger storms cannot be completely ruled out.

Additional opportunities for showers and thunderstorms will remain in the forecast through the weekend and into early next week. It is important to note that this does not mean continuous rainfall. There will be many dry hours between periods of scattered storms. However, the more humid air mass combined with daytime heating will create an environment favorable for afternoon and evening thunderstorm development on several days.

Temperatures throughout the extended forecast will continue running near to slightly above normal for early June. Highs will generally reach the middle and upper 80s through the weekend and early next week, with overnight lows settling into the 60s. Any areas that experience thunderstorms could see slightly cooler temperatures due to cloud cover and rainfall.

Overall, enjoy the next couple of days of sunshine, low humidity, and comfortable temperatures. Summer warmth and humidity will gradually return by the weekend, along with periodic chances for showers and thunderstorms across the region.

First Warn Weather. First. Accurate. Trusted.

First Warn Forecast
Tuesday, June 2, 2026
Comfortable Summer Weather Settles Into the Region

After Monday’s active thunderstorms, much quieter and more comfortable weather has settled across Missouri and Illinois as we begin the first full week of meteorological summer. A large area of high pressure stretching from the Great Lakes into the eastern United States will control the weather pattern through Thursday, bringing sunshine, lower humidity, and seasonable temperatures to the Mid-Mississippi Valley.

A backdoor cold front moved through the area overnight, allowing noticeably drier air to filter into the region. Dew points have dropped considerably compared to the sticky conditions experienced over the weekend and Monday, making it feel much more pleasant outside. The combination of low humidity, light winds, and plenty of sunshine will create nearly picture-perfect early June weather for both today and Wednesday.

Afternoon temperatures will climb into the upper 70s to lower 80s each day, which is very close to average for this time of year. Even better, overnight lows will drop comfortably into the 50s thanks to excellent radiational cooling conditions under mostly clear skies. Open windows weather has officially arrived, at least for a couple of days.

Warmth and Humidity Begin Returning Thursday

The quiet stretch of weather will continue into Thursday, although subtle changes in the overall pattern will begin taking shape. Winds will gradually turn back to the south, allowing warmer and slightly more humid air to return northward into Missouri and Illinois. Temperatures Thursday afternoon are expected to rise into the low and middle 80s while humidity levels slowly begin increasing once again.

While Thursday itself is expected to remain dry, the atmosphere will begin preparing for a more unsettled pattern heading into the end of the week. Moisture returning from the Gulf of Mexico combined with an approaching upper-level disturbance from the Plains will eventually increase the chances for showers and thunderstorms.

Storm Chances Return Late Week Into the Weekend

Forecast guidance continues to indicate increasing chances for showers and thunderstorms beginning Friday and continuing through the weekend into early next week. The first round of storms may begin developing Friday across eastern Kansas and western Missouri before gradually spreading eastward into parts of central and northeast Missouri later in the day.

Some uncertainty still exists regarding how widespread storms will become Friday afternoon across southeast Missouri, the St. Louis metro, and southwest Illinois. Current indications suggest instability may weaken somewhat as storms move east, which could limit severe weather potential locally during the daytime hours Friday. However, increasing moisture and persistent southerly flow Friday night into Saturday may allow additional rounds of showers and thunderstorms to spread across much of the region.

The forecast becomes more complicated by late weekend into early next week as weather models begin showing differences in the overall upper-level pattern. Some solutions favor slightly drier conditions while others keep warm, humid, and stormy weather locked across the Midwest. At this point, the most likely scenario appears to favor periodic chances for showers and thunderstorms continuing through Monday.

Temperatures through the extended forecast are expected to remain seasonably warm with afternoon highs generally in the middle to upper 80s and overnight lows in the middle to upper 60s. Of course, daily storm chances and cloud cover could cause temperatures to fluctuate from day to day.

For now, enjoy the refreshing break from humidity and severe weather through midweek because summer heat and storm chances are already preparing for another comeback.

First. Accurate. Trusted.

FirstWARN Alert: Flood Warning for Boone County in MO. From Meteorologist Nick Palisch

First Warn Forecast
Monday, June 1, 2026
First Day of Meteorological Summer Begins with Storms
Strong Storms Possible Today Across Missouri and Illinois

Meteorological summer officially begins today, but instead of sunshine and calm skies, the region is starting the season with an active weather pattern. Multiple rounds of thunderstorms are expected across Missouri and Illinois today, and some of these storms could become strong to severe. The primary threats will include damaging winds, large hail, torrential rainfall, and localized flooding. Anyone with outdoor plans today should remain weather aware and have a way to receive warnings, especially through this afternoon and evening.

Thunderstorms that developed overnight across Missouri continue to strengthen early this morning as they move eastward into the First Warn viewing area. These storms are feeding off a strong low-level jet and a very moist atmosphere capable of supporting heavy rainfall and strong thunderstorm development. Forecasters are monitoring the potential for some of these storms to organize into a stronger line segment capable of producing pockets of damaging winds. Hail will also be possible with the strongest cells. Rainfall rates may become intense at times, and areas that experience repeated storms could see localized flooding concerns develop quickly.

The first round of storms is expected to move east of the area by mid to late morning, bringing at least a temporary break in the action for many locations. However, the atmosphere will remain unstable behind the morning storms. Boundaries left over from the earlier convection are expected to become the focus for additional thunderstorm development this afternoon and early evening, especially across southeast Missouri and southwest Illinois. Communities from Farmington to Cape Girardeau and across southern Illinois into Marion and Carbondale may see another round of stronger storms later today.

Heavy Rain, Damaging Winds, and Hail Main Concerns

The environment this afternoon will remain favorable for severe weather development. Forecast models continue to indicate moderate to strong instability with enough wind shear to support organized thunderstorms capable of producing damaging straight-line winds and large hail. While the tornado threat appears limited at this time, isolated stronger storms cannot be ruled out, especially where boundaries interact during peak heating this afternoon.

Heavy rainfall will continue to be a concern as tropical-like moisture remains in place across the region. Some storms may produce very heavy rain in a short period of time, leading to ponding on roadways and isolated flooding issues in low-lying or poor drainage areas. Drivers should use caution during periods of heavy rain, as visibility may quickly drop and roads could become slick.

Temperatures today will recover back into the lower and middle 80s despite the morning storms. Humidity levels will remain elevated ahead of the cold front, making it feel quite muggy throughout the day. Once storms begin to exit this evening, drier air will gradually move into the region overnight.

Drier and Quieter Weather Arrives Midweek

After today’s active weather, a much quieter pattern is expected to settle into the region through the middle part of the week. High pressure building southward out of the Upper Midwest will bring several days of dry weather along with slightly cooler temperatures and lower humidity. Tuesday through Thursday are shaping up to be pleasant early summer days with a mix of sunshine and seasonable warmth.

High temperatures on Tuesday will likely remain in the upper 70s to lower 80s before warmer conditions return by mid to late week. Afternoon highs are expected to climb back into the middle and upper 80s by Thursday and Friday as southerly winds return and humidity gradually increases once again.

The next opportunity for showers and thunderstorms appears to arrive later this week into next weekend as another storm system develops across the western United States and pushes moisture back north into the Midwest. While it is too early to determine severe weather potential, the pattern does appear active heading into the upcoming weekend.

For now, the main focus remains on today’s storm chances and the potential for severe weather during both the morning and afternoon rounds of thunderstorms. Stay weather aware and continue to monitor the latest forecasts and alerts throughout the day.

First. Accurate. Trusted.