St
Donatus has cold, snowy winters and pleasant summers. A typical July afternoon reaches 83°, a January night drops to 12°, and about 43 inches of snow falls in a normal winter.
A year in St. Donatus at a glance
Each month’s typical high and low, and what it brings.
What stands out about St. Donatus’s climate
Read from where St. Donatus sits among Iowa’s towns. The page puts what stands out first.
43 inches of snow, 38 of rain and melt
June is the wettest month and January the driest. Rain or snow falls on about 118 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
What a year in St. Donatus feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 165 frost-free days a year
In half of years the last 32° night comes by April 28 and the first by October 11.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Living with St. Donatus’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
165 frost-free days. The last frost comes by Apr 28 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 11.
About 43" a winter over 13 days with an inch or more, most in January. Snow covers the ground about 64 days a year.
Months averaging under 55° run from October through April. Heating is 92% of the year’s heating-and-cooling load.
About 6 days a year reach 90°, and July afternoons average 83°.
The nicest months are May, June, July, August and September. 0.0 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →Warmer than it used to be
The last 30 years in St. Donatus averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.0°).
A smaller shift than in 78% of U.S. towns.
Change by month
How St. Donatus compares
Against every U.S. town on TownTapestry, each counted once, with its place in Iowa.
St. Donatus weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 28° | 12° | 1.3" | 10.7" | 9 | 21 | 10° – 32° |
| February | 32° | 16° | 1.5" | 10.6" | 9 | 18 | 11° – 37° |
| March | 45° | 27° | 2.2" | 5.7" | 10 | 8 | 28° – 51° |
| April | 59° | 38° | 3.8" | 1.9" | 11 | 1 | 39° – 55° |
| May | 71° | 49° | 4.3" | 0 | 13 | 0 | 54° – 67° |
| June | 80° | 59° | 5.6" | 0 | 12 | 0 | 66° – 73° |
| July | 83° | 63° | 4.8" | 0 | 10 | 0 | 66° – 80° |
| August | 81° | 61° | 4.0" | 0 | 9 | 0 | 65° – 78° |
| September | 74° | 53° | 3.7" | 0 | 9 | 0 | 58° – 69° |
| October | 61° | 41° | 3.0" | 0.5" | 9 | 0 | 46° – 57° |
| November | 46° | 29° | 2.3" | 2.8" | 8 | 3 | 30° – 48° |
| December | 33° | 18° | 1.8" | 10.3" | 9 | 13 | 12° – 36° |
| Year | 58° | 39° | 38.3" | 42.5" | 118 | 64 |
Heating and cooling a home in St. Donatus
92% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 11° to 37°. June is the most reliable, staying within 7°.
Common questions about St. Donatus’s climate
What is the coldest month in St. Donatus?
January, with a typical high of 28° and a low of 12°.
What is the hottest month in St. Donatus?
July, with a typical high of 83° and a low of 63°. About 6 days a year reach 90°.
How much snow does St. Donatus get?
About 43 inches in a normal winter, most of it in January.
When is the first frost in St. Donatus?
In half of years the first 32° night comes by October 11, and the last spring frost by April 28.
What is the rainiest month in St. Donatus?
June, with 5.6 inches of rain and melted snow. The year totals 38 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in St. Donatus.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for St. Donatus itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Dubuque Rgnl Airport, IA (9 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.