vlog

Skip to content
NOWCAST vlog News at 6pm Weekday Evening
Watch on Demand
Advertisement

Why cloudy skies often dominate this time of year

Tired of the gray weather? 'Tis the season for clouds, unfortunately

Why cloudy skies often dominate this time of year

Tired of the gray weather? 'Tis the season for clouds, unfortunately

YEAH, THAT IS FOR SURE. AS WE GET CLOSER TO THE NEW YEAR, THAT’S A GOOD IDEA TO START PLANNING, AT LEAST FOR THAT. WEATHER HEADLINES TO START THINGS OFF THIS MORNING. WELL, IT’S A FOGGY ONE. YOU DON’T EVEN WANT TO BE OUTSIDE, LET ALONE TAKE DOWN SOME CHRISTMAS DECORATIONS. AS WE CONTINUE THROUGH THE REST OF TODAY, THAT DENSE FOG IS GOING TO STICK AROUND THROUGHOUT THE MORNING. RAIN. PRACTICALLY ALL DAY LONG. IT’S GOING TO BE STAYING LIGHT. THERE IS SOME SUN THIS WEEKEND, SO ANYTHING OUTDOORS IS STARTING TO LOOK BETTER AND BETTER AS WE GET INTO SATURDAY AND INTO SUNDAY. BUT AS OF RIGHT NOW, YOU’RE WAKING UP TO VERY REDUCED VISIBILITIES ACROSS DES MOINES AND ACROSS THE METRO, GOING FARTHER NORTH, SOUTH, EAST AND WEST. PICK A DIRECTION. THERE’S GOING TO BE FOG AS WE START THINGS OFF, AS TEMPERATURES ARE MAINLY IN THE MID AND UPPER 40S AND LOW 40S FARTHER NORTH. LITTLE COOLER. BUT ALL IN ALL, WE ARE ALL GOING TO BE ABOVE THE FREEZING POINT WITH THE RAINFALL STICKING AROUND, BECOMING A LITTLE BIT MORE WIDESPREAD NOW, ESPECIALLY HERE IN CENTRAL IOWA, GOING ALL THE WAY UP INTO NORTHERN IOWA, INTO SOUTHERN MINNESOTA. SO A PRETTY CONSISTENT RAIN. IF I-35 NORTHBOUND FROM DES MOINES IS IN YOUR PLANS TODAY, YOU’RE GOING TO BE USING THOSE WINDSHIELD WIPERS. GIVE YOURSELF SOME EXTRA TIME. TAKE IT SLOW. DON’T BE IN A RUSH TODAY. LOWERED VISIBILITIES, WET ROADS. THEY DON’T COMBINE VERY WELL. WE’RE GOING TO CONTINUE WITH MORE OF THIS LIGHT RAINFALL PICKING UP THROUGHOUT THE MORNING. THIS IS 12:00. SO LUNCHTIME ALL THE WAY THROUGH THE REST OF THE AFTERNOON. THE DAYLIGHT HOURS WE ARE SEEING VERY CONSISTENT LIGHT RAIN. IT’S A WASH OUT IN THAT ASPECT. AND AS WE GET INTO THE EVENING HOURS, THIS IS 10:00. IT’S JUST NOW MOVING NORTH OF I-80 AND IT WILL STILL BE HOLDING ON TO NORTH CENTRAL AND NORTHEASTERN IOWA, BUT IT WILL BE WINDING DOWN OVERNIGHT TONIGHT. TOMORROW MORNING WE’RE GOING TO BE MOSTLY DRY. STILL A CHANCE FOR SOME PATCHY FOG SINCE WE DO HAVE STILL AN ABUNDANCE OF MOISTURE AT THE GROUND LEVEL. SO THAT’S GOING TO BE GREAT CONDITIONS FOR FOG TO REFORM. BUT AS WE GO INTO THE NOON HOUR AND FOR THE AFTERNOON, YOU START TO SEE SOME BREAKS. HAVEN’T SEEN ANYTHING LIKE THIS IN A WHILE. SO WE COULD BE ACTUALLY LOOKING AT OUR FIRST DOSE OF SUNSHINE. AT LEAST THE POSSIBILITY OF IT AS WE GET INTO SATURDAY AFTERNOON RAINFALL TOTALS BETWEEN NOW AND FRIDAY NIGHT CAN BE RANGING FROM AROUND A QUARTER UP TO AROUND THREE QUARTERS OF AN INCH, SO IT’S A PRETTY DECENT DOSE FOR THIS LATE IN THE YEAR. 40S FOR HIGHS TODAY WERE SCATTERED SHOWERS. MORE DENSE FOG IS EXPECTED THROUGHOUT THE MORNING. IT IS GOING TO BREAK UP FOR THE AFTERNOON. THAT DENSE FOG ADVISORY EXPIRES AT NOON AS WELL. SATURDAY. LIKE I SAID, CHANCE FOR SUN ALSO FOR SUNDAY, BUT A CHANCE FOR SOME MORNING RAIN WILL STILL BE POSSIBLE SUNDAY MORNING. THEN NEXT WEEK, MONDAY, GOING INTO TUESDAY, RAINFALL RETURNS SWITCHES OVER TO SNOW. MONDAY NIGHT GOING INTO TUESDAY COULD BE WAKING UP SOME SLICK ROADS O
Advertisement
Why cloudy skies often dominate this time of year

Tired of the gray weather? 'Tis the season for clouds, unfortunately

Yearning for sunshine? Unfortunately, we're at the peak time of year for clouds in Iowa.December — closely followed by January — is historically the cloudiest month on the calendar.Since 1951, Des Moines has experienced overcast skies at noon on 52% of December days. For comparison, the same only happens 25% of the time in July.Why more clouds in winter?Lower temperatures are mainly to blame.Colder air is more easily saturated than warm air. That means the atmosphere doesn't need to be moistened or cooled as much for cloud droplets to form.Winter days are also short, and the sun stays lower in the sky. This makes it harder to warm the ground, making something called a temperature inversion more common.During inversions, the air is actually warmer well above ground level than at the surface. Moisture can get trapped under this inversion, leading to stubborn low-level stratus clouds.That trapped moisture often comes from another feature of winter: snowpack. Snow on the ground melts or sublimates into the atmosphere, fueling low clouds and fog.December is also typically the foggiest month of the year in central Iowa.

Yearning for sunshine? Unfortunately, we're at the peak time of year for clouds in Iowa.

December — closely followed by January — is historically the cloudiest month on the calendar.

Advertisement

Since 1951, Des Moines has experienced overcast skies at noon on 52% of December days. For comparison, the same only happens 25% of the time in July.

iowa clouds
Hearst Owned
12 p.m. daily observations in Des Moines, 1951-2024. Data from Iowa Environmental Mesonet.

Why more clouds in winter?

Lower temperatures are mainly to blame.

Colder air is more easily saturated than warm air. That means the atmosphere doesn't need to be moistened or cooled as much for cloud droplets to form.

Winter days are also short, and the sun stays lower in the sky. This makes it harder to warm the ground, making something called a temperature inversion more common.

During inversions, the air is actually warmer well above ground level than at the surface. Moisture can get trapped under this inversion, leading to stubborn low-level stratus clouds.

That trapped moisture often comes from another feature of winter: snowpack. Snow on the ground melts or sublimates into the atmosphere, fueling low clouds and fog.

December is also typically the foggiest month of the year in central Iowa.