If you’re making plans for St. Patrick’s Day in Iowa, you’ll find the weather can shape your whole experience. Most years, highs hit the upper 40s and lows dip into the mid-20s, but honestly, the day has delivered everything from warm sunshine to blizzards. That range makes it one of the more unpredictable spring holidays here.
You might step outside and feel that mild air hinting that spring’s finally arrived. Or, you could get hit with a sharp chill that says winter’s not going quietly.
Rain can show up, snow’s never off the table, and sometimes you luck out with clear skies that make outdoor celebrations a breeze.
Looking at what usually happens around this date helps you get ready for both the fun and the curveballs. Whether you’re aiming to watch a parade, join a local festival, or travel across Iowa, knowing the typical temperature, precipitation, and sunshine patterns gives you a better shot at planning.
Typical Temperature Patterns for St. Patrick’s Day
Temperatures around St. Patrick’s Day in Iowa usually sit in the cool early-spring range, but honestly, they swing a lot from year to year. One year, you might get a mild afternoon in the 50s, while another year, you’ll be bundled up against cold that still feels like winter.
Average Highs and Lows
On March 17, the average high temperature across Iowa lands in the mid-40s to low 50s°F. Northern cities stay cooler, and southern spots often sneak a few degrees warmer.
The average low temperature usually sits in the upper 20s to low 30s°F. If the night’s clear, it can feel straight-up wintry as heat escapes.
You’ll probably wake up to a chilly morning that warms up a bit by afternoon. It’s not as harsh as January, but there’s still a late-winter bite in the air. Layers or a light jacket usually make outdoor events more comfortable.
Temperature Extremes on Record
Iowa’s seen both bitter cold and weirdly warm St. Patrick’s Days. Some years, records show highs in the 70s or even low 80s°F during rare warm spells.
Nearby La Crosse, WI, and Rochester, MN, hit the 80s in 2012, and Iowa felt the same warmth.
But some years, highs barely scrape into the teens, with subzero lows in northern Iowa. In 1941, the region shivered through one of the coldest March 17ths ever, with single-digit highs and lows far below zero.
So, you could get spring-like warmth or a blast of lingering winter. That’s Iowa for you.
Day-to-Day Variability
Even in the same week, temperatures can flip fast. A cold front might drop highs by 20 degrees in a day, or a warm southern wind brings a quick thaw.
Snow cover changes things too. Bare ground lets the sun warm the air faster, while leftover snow keeps highs muted and nights colder.
With all that, planning gets tricky. You’ll want to check the forecast often, since Iowa’s mid-March weather can swing from lovely to brutal in a hurry.
Precipitation Trends and Probabilities
St. Patrick’s Day in Iowa can bring a mix of wet and dry, and both rain and snow are fair game. Weather records show heavy storms aren’t super common, but light precipitation pops up often enough to mess with travel and outdoor plans.
Likelihood of Rain or Snow
Most years, you’re looking at about a 40–50% shot at some kind of precipitation on March 17. That could mean rain or snow, depending on how cold it is.
Light rain showers happen more in southern Iowa, while the north gets more snow chances. You’ll see more days with just a trace than with measurable amounts, but both show up in the records.
Snow’s less frequent than rain, but it’s still possible. Nearby regions report measurable snow on about 15–20% of St. Patrick’s Days. Trace amounts show up even more, especially when temps hover near freezing.
Average Precipitation Amounts
On average, Iowa picks up about 0.05–0.10 inches of precipitation on March 17. It’s not much compared to later in spring or summer, but it’s enough to make roads slick or turn fields muddy.
Snowfall averages less than half an inch. Some years, though, a strong late-season system dumps several inches. La Crosse, WI, once got over 8 inches on St. Patrick’s Day.
Rainfall is usually light, but steady showers can happen. Most wet days bring less than half an inch, but heavier events, while rare, have definitely shown up and can mess with parades or gatherings.
Notable Wet and Dry Years
Weather history in Iowa for St. Patrick’s Day is all over the map. Some years stay bone dry, while others see measurable rain or snow.
In 1965, a major blizzard slammed parts of Iowa and neighboring states, closing roads and stranding travelers. Snowdrifts piled up, and schools shut down.
Other years, not a drop falls. Dry St. Patrick’s Days can be just as memorable, especially if the weather’s mild and you’re outside.
Sunshine and Cloud Cover
Mid-March in Iowa brings wild swings between sunshine and clouds. Some years, bright skies make it feel like spring, while others are stuck in gray with barely a peek of sun.
These differences really shape the vibe, even if the temperatures don’t change much.
Typical Sunshine Hours
By mid-March, Iowa gets over 11½ hours of daylight. The sun rises around 7:20 AM and sets close to 7:20 PM, which is a real sign spring’s creeping in.
On average, you’ll get 4 to 6 hours of sunshine per day around St. Patrick’s Day. Some years, it’s more than 7 hours. Other years, stormy weather cuts it down to less than 2.
That extra daylight gives you more chances to enjoy outdoor events, even if clouds are around. Sunshine also makes those 40s or 50s feel a lot warmer than they sound.
Cloudy Versus Clear Days
Clouds play a big part in Iowa’s March weather. Records show about 60–70% of March days are at least partly cloudy. So, a totally clear sky is kind of rare.
You’ll probably see a mix:
- Cloudy days usually keep highs in the 30s and 40s.
- Partly sunny days can push into the 50s or higher.
- Overcast skies sometimes mean light rain or snow, but a lot of St. Patrick’s Days stay dry.
Clear days do happen, but don’t count on them. When you get one, it usually means a colder morning since heat escapes fast overnight. So, a sunny day can still start out frosty.
Snowfall and Blizzard Conditions
Most St. Patrick’s Days in Iowa bring light snowfall, but history proves major winter storms can hit this time of year. Average totals are small, but rare blizzards have made their mark.
Average Snowfall on March 17
Snowfall on March 17 in Iowa is usually pretty limited, with many years seeing little or nothing. On average, you’ll get less than an inch across most of the state.
Cities like Waterloo, Cedar Rapids, and Iowa City don’t see measurable snow every year.
But exceptions happen. Waterloo picked up about half a foot in 1965, and that year stands out—multiple eastern Iowa cities got their snowiest St. Patrick’s Day on record.
Here’s how it usually looks:
| Location | Avg. Snowfall (March 17) | Notable Maximum Recorded |
|---|---|---|
| Waterloo | <1 inch | ~6 inches (1965) |
| Cedar Rapids | <1 inch | ~6 inches (1965) |
| Iowa City | <1 inch | ~6 inches (1965) |
So, while snow is usually minor, heavy snow is definitely possible.
Frequency of Blizzard Events
Blizzard conditions on March 17 are rare, but they’ve happened. The 1965 St. Patrick’s Day blizzard is the big one. Eastern Iowa got hammered with heavy snow and strong winds, making whiteouts.
Minnesota had it even worse, with some spots getting over two feet. In Iowa, drifts blocked roads and rural areas took the brunt.
Events like that are rare, but they show how quickly things can change. One year, you’ll have mild weather, and the next, you might be digging out from a blizzard. That’s just part of Iowa’s weather story.
Severe Weather Events
By mid-March, Iowa’s weather can throw more than just mild spring days at you. Records show thunderstorms, strong winds, and even reduced visibility from blowing snow or dust have all caused issues during St. Patrick’s Day celebrations.
Thunderstorm Occurrences
March doesn’t see as many thunderstorms as later spring, but they do pop up. Around St. Patrick’s Day, storms can bring lightning, heavy rain, and small hail.
Severe storms with damaging hail or tornadoes are rare but possible since Iowa sits in a central U.S. storm zone.
Sometimes, strong systems in mid-March pull warm, moist air north and kick off early-season thunderstorms. Past events have even brought 70s and 80s, fueling storms that feel out of place for the time of year.
If you’re traveling or heading to outdoor events, keep an eye on the short-term forecast. Even a quick March thunderstorm can disrupt parades, travel, or gatherings. Lightning is a real risk for anyone outside, even during a short shower.
Wind and Visibility Issues
Wind is a big deal in Iowa during March. Passing storm systems often bring strong gusts, and these can make it uncomfortable or even risky to be outside. Gusts over 40 mph aren’t unusual, especially when cold and warm air masses meet.
Visibility sometimes drops from blowing snow if a late-season storm hits. With deeper snowpacks, drifts can block rural roads and slow down travel. The 1965 blizzard is a classic example—roads closed, and travel stopped.
Dust can cut visibility in dry years when fields are bare, though that’s less common than snow. Still, it’s part of Iowa’s March weather. Staying alert to wind speeds and road conditions can help you avoid surprises.
Daily Weather Timeline on St. Patrick’s Day
You’ll notice a steady daylight rhythm and temperatures that shift from chilly mornings to milder afternoons. Conditions change year to year, but these patterns help you plan outdoor events or travel with a bit more confidence.
Sunrise and Sunset Times
In mid-March, Iowa gets about 12 hours of daylight. Sunrise usually happens close to 7:20 AM, and sunset comes around 7:20 PM.
March 17 feels like one of those rare days when day and night split almost evenly. The sun rises later than it does in summer, so mornings often feel cold and kind of gloomy.
By the time sunset rolls around, temperatures start dropping again, and you remember winter’s still hanging on. If you’re planning early activities like parades or a morning walk, you’ll want to dress for chilly air and maybe even frost.
Evening gatherings stick around in daylight until early evening, but you should bring a jacket since it gets cold fast after the sun goes down.
Typical Day Forecast
On St. Patrick’s Day in Iowa, average highs usually land in the mid-40s to low 50s (°F). Lows dip into the upper 20s or low 30s, so mornings can be pretty brisk.
Some years, the temperature might surprise you and climb into the 60s. Other times, it barely gets above freezing.
Snow doesn’t show up much, but it’s not impossible, and light rain showers happen more often than big storms.
A typical day plays out like this:
- Morning (7–10 AM): Cold, often right around freezing.
- Afternoon (12–4 PM): This is the warmest stretch, usually somewhere in the 40s or 50s.
- Evening (6–9 PM): Temps drop fast, sometimes by 10–15 degrees.
It’s smart to dress in layers, so you can peel off a jacket or sweater as the day warms up and add it back when things cool down.
Historical Weather Highlights
Weather around St. Patrick’s Day in Iowa can swing from mild, spring-like afternoons to mornings that feel like mid-winter. When you look at past records, you get a sense of both the oddball years and the bigger climate patterns that shape the holiday.
Memorable St. Patrick’s Day Weather
March 17 in Iowa can really bring anything. Some years, you get sunny skies and highs in the 60s, which makes outdoor events and parades a lot more fun. Other years, especially up north, you might wake up to snowfall and freezing temperatures.
Des Moines has seen it all—some St. Patrick’s Days with snow on the ground, and others that shot up well into the 70s. Over in eastern Iowa, places like Iowa City and Cedar Rapids have had both late-season snow showers and mild, breezy afternoons, sometimes in the same decade.
Wind often comes into play too. Strong gusts blow in with cold fronts during mid-March, and that can make it feel way colder than what the thermometer says.
Rain isn’t super common, but it happens, and sometimes it turns parade routes into a muddy mess. These swings show just how quickly things can flip in the Midwest during early spring.
If you’re heading out for events, it’s always smart to be ready for both winter and spring weather.
Long-Term Climate Trends
Iowa’s climate data stretches back over a century. Around March 17, you’ll usually see average highs in the upper 40s to low 50s°F.
Average lows tend to fall in the upper 20s or low 30s°F. These numbers give you a general idea of what’s typical, but honestly, the weather can swing wildly from year to year.
Spring seems to show up a little earlier now than it used to. In recent decades, central and southern Iowa have started seeing more warm St. Patrick’s Days than before.
Snow on the holiday hasn’t vanished, but it pops up less often than it did back in the early 1900s.
Precipitation this time of year is all over the place. Some years, there’s barely a hint of rain or snow. Other times, you might get a light dusting.
Every now and then, a strong storm rolls through, bringing heavier snow or a chilly rain. March in Iowa still keeps you guessing, doesn’t it?
Des Moines, Sioux City, and Iowa City all show the same pattern in their climate records. You can usually expect cool weather that’s slowly trending warmer, but you really should stay ready for a sudden cold snap or a quick snow shower during St. Patrick’s week.