Photo: I, the copyright holder of this work, hereby publish it under the following license: · CC BY-SA 3.0Watertown has colder winter nights than 92% of U.S. towns
Expect July afternoons of about 82°. A year here swings 71° from midwinter lows to midsummer highs. Its July afternoons stay fresher than in 80% of U.S. towns. Tender plants can go out after about April 28; in half of years the first frost comes by October 12.
A year in Watertown at a glance
Each month’s typical high and low, and what it brings.
What stands out about Watertown’s climate
Compared with towns across the U.S., with Watertown’s place in Wisconsin beside it.
What a year in Watertown feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 167 frost-free days a year
In half of years the last 32° night comes by April 28 and the first by October 12. Frost and day counts come from NOAA’s station at Watertown Wwtp, WI, 1.1 miles from the town’s center, at about the same height.
The 2023 USDA map puts Watertown’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −15°. 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 37 inches of snow a winter
Snow, measured at Watertown Wwtp, WI, falls mostly in January. Precipitation (rain plus melted snow) adds up to 36 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 123 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Watertown
93% 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 Watertown Wwtp, WI.
Living with Watertown’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
167 frost-free days in zone 5b. 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 12.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 5.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Watertown from natural hazards, river flooding is the largest share (44%); heat waves, cold waves, winter storms and ice storms together are 24%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Watertown and its neighbors
Every town next door is within a degree of Watertown in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Watertown’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 |
|---|---|---|---|---|
| Watertown, WI | 12° | 82° | 36" | 37" |
| Boone, IA | 11° | 84° | 36" | 36" |
| Winona, MN | 8° | 83° | 36" | 38" |
| Milford, MI | 15° | 82° | 33" | 36" |
| Horseheads, NY | 16° | 82° | 36" | 42" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Watertown averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.5°).
A smaller shift than in 76% 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 Watertown compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Watertown’s place among Wisconsin’s.
Watertown weather by month
Highs, lows and precipitation from NOAA’s grid at Watertown’s center; snow, wet days and snow on the ground from Watertown Wwtp, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 27° | 12° | 1.4" | 11.0" | 8 | 21 | 9° – 32° |
| February | 31° | 15° | 1.4" | 9.7" | 8 | 19 | 11° – 35° |
| March | 43° | 25° | 2.0" | 4.4" | 8 | 7 | 25° – 49° |
| April | 57° | 35° | 3.7" | 1.6" | 12 | 1 | 36° – 52° |
| May | 69° | 47° | 4.1" | 0.1" | 13 | 0 | 51° – 63° |
| June | 78° | 57° | 5.0" | 0.0" | 12 | 0 | 64° – 72° |
| July | 82° | 61° | 4.0" | 0.0" | 11 | 0 | 66° – 78° |
| August | 80° | 59° | 4.1" | 0.0" | 10 | 0 | 64° – 75° |
| September | 73° | 51° | 3.3" | 0.0" | 10 | 0 | 56° – 67° |
| October | 60° | 40° | 2.8" | 0.3" | 11 | 0 | 45° – 56° |
| November | 45° | 29° | 2.2" | 1.4" | 9 | 2 | 28° – 46° |
| December | 33° | 18° | 1.7" | 8.5" | 10 | 12 | 12° – 36° |
| Year | 56° | 37° | 35.5" | 37.0" | 123 | 63 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 12° to 36°. June is the most reliable, staying within 8°.
Where Watertown’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 Watertown’s center.
- Snow: Watertown Wwtp, WI (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Watertown Wwtp, WI, 1.1 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 Watertown’s climate
What is the weather like in Watertown?
A typical July afternoon reaches 82°, a January night drops to 12°, and about 37 inches of snow falls in a normal winter. Colder January nights than 92% of U.S. towns; cooler July afternoons than 80% of U.S. towns.
How cold does it get in Watertown in winter?
January nights average 12°. About 149 nights a year reach 32° or below and 18 reach 0° or below. In the coldest January of the last 30 years the month averaged 9°.
How much snow does Watertown get?
About 37 inches in a normal winter at Watertown Wwtp, WI, most of it in January, with snow on the ground about 63 days a year.
How hot does it get in Watertown?
July, with a typical high of 82° and a low of 61°. About 7 days a year reach 90° (Watertown Wwtp, WI).
When is the first and last frost in Watertown?
In half of years the last spring frost (32°) comes by April 28 and the first fall frost by October 12, about 167 frost-free days, at Watertown Wwtp, WI.
What growing zone is Watertown in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −15°.
What is the best time of year to visit Watertown?
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 Watertown getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 76% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Watertown.
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.