Photo: Royalbroil · CC BY-SA 3.0Theresa has colder winter nights than 93% of U.S. towns
On a normal July day the thermometer tops out near 81°. Rain follows the seasons: June brings about 3.8 times as much as February. By July afternoons alone, it runs cooler than 87% of U.S. towns. Warm coats and heating bills mark the months from October to April, when means dip under 50°.
A year in Theresa at a glance
Each month’s typical high and low, and what it brings.
What stands out about Theresa’s climate
Compared with towns across the U.S., with Theresa’s place in Wisconsin beside it.
What a year in Theresa feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 158 frost-free days a year
In half of years the last 32° night comes by May 1 and the first by October 10. Frost and day counts come from NOAA’s station at Horicon Wwtp, WI, 10 miles from the town’s center, at about the same height.
The 2023 USDA map puts Theresa’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −16°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 41 inches of snow a winter
Snow, measured at Horicon Wwtp, WI, falls mostly in January, February and December. Precipitation (rain plus melted snow) adds up to 34 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 114 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Theresa
94% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Horicon Wwtp, WI.
Living with Theresa’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
158 frost-free days in zone 5a. The last frost comes by May 1 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 10.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Theresa from natural hazards, river flooding is the largest share (44%); heat waves, cold waves, winter storms and ice storms together are 23%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Theresa and similar climates
TownRatings has no climate map of the towns around Theresa yet.
Climates most like Theresa’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Theresa, WI | 10° | 81° | 34" | 41" |
| Plattsburgh, NY | 9° | 81° | 35" | 50" |
| Woodbury, MN | 7° | 82° | 33" | 40" |
| Clear Lake, IA | 7° | 82° | 36" | 44" |
| Colchester, VT | 10° | 81° | 38" | 50" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Theresa averaged 1.1° warmer than the 1900s. The biggest change is in December (+2.8°).
A smaller shift than in 67% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Theresa compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Theresa’s place among Wisconsin’s.
Theresa weather by month
Highs, lows and precipitation from NOAA’s grid at Theresa’s center; snow, wet days and snow on the ground from Horicon Wwtp, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 26° | 10° | 1.4" | 10.9" | 9 | 24 | 7° – 30° |
| February | 30° | 13° | 1.3" | 10.1" | 8 | 22 | 10° – 33° |
| March | 42° | 23° | 1.9" | 5.2" | 9 | 10 | 24° – 47° |
| April | 55° | 34° | 3.4" | 1.7" | 11 | 1 | 34° – 50° |
| May | 67° | 45° | 3.9" | 0.0" | 12 | 0 | 49° – 62° |
| June | 77° | 55° | 4.8" | 0.0" | 11 | 0 | 62° – 71° |
| July | 81° | 59° | 3.9" | 0.0" | 10 | 0 | 65° – 77° |
| August | 79° | 58° | 3.9" | 0.0" | 9 | 0 | 63° – 74° |
| September | 72° | 50° | 3.3" | 0.0" | 9 | 0 | 54° – 66° |
| October | 59° | 39° | 2.9" | 0.4" | 10 | 0 | 44° – 55° |
| November | 44° | 27° | 2.1" | 2.3" | 9 | 3 | 26° – 45° |
| December | 31° | 17° | 1.6" | 10.2" | 9 | 16 | 11° – 35° |
| Year | 55° | 36° | 34.4" | 40.8" | 114 | 76 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 7° to 30°. June is the most reliable, staying within 8°.
Where Theresa’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Theresa’s center.
- Snow: Horicon Wwtp, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Horicon Wwtp, WI, 10 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Theresa’s climate
What is the weather like in Theresa?
A typical July afternoon reaches 81°, a January night drops to 10°, and about 41 inches of snow falls in a normal winter. Colder January nights than 93% of U.S. towns; cooler July afternoons than 87% of U.S. towns.
How cold does it get in Theresa in winter?
January nights average 10°. About 155 nights a year reach 32° or below and 21 reach 0° or below. In the coldest January of the last 30 years the month averaged 7°.
How much snow does Theresa get?
About 41 inches in a normal winter at Horicon Wwtp, WI, most of it in January, February and December, with snow on the ground about 76 days a year.
How hot does it get in Theresa?
July, with a typical high of 81° and a low of 59°. About 6 days a year reach 90° (Horicon Wwtp, WI).
When is the first and last frost in Theresa?
In half of years the last spring frost (32°) comes by May 1 and the first fall frost by October 10, about 158 frost-free days, at Horicon Wwtp, WI.
What growing zone is Theresa in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −16°.
What is the best time of year to visit Theresa?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Theresa getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 67% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Theresa.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.