Janesville in Spring
In spring (March, April and May), Janesville sees average daytime highs around 56°F and overnight lows near 39°F, with 10.3 in of precipitation over about 34 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs climb from about 38°F in early March to 73°F by late May. The sky is clear or mostly clear about 23% of the time across spring, and the air most often feels dry.
Spring is Janesville's 3rd-best season to visit on our travel score. For the whole year in context, see Janesville's year-round climate.
- Avg daytime high
- 56°F
- 3rd-warmest season
- Avg overnight low
- 39°F
- Precipitation
- 10.3 in
- 34 wet days
- Avg wind
- 8 mph
- Travel score
- 3.5
- 3rd-best season
- Months
- Mar · Apr · May
Temperature in Janesville in Spring
Over the season highs climb from about 38°F in early March to 73°F by late May.
A typical spring day in Janesville reaches about 56°F and drops to 39°F overnight. The warmest of the three months is May, the coolest March.
How spring really feels in Janesville
Once humidity and wind are folded in, spring brings about 0 days that feel above 90°F and 45 that feel at or below 32°F.
The story in spring is cold — wind chill drags the overnight "feels like" below the raw low.
Janesville weather by month
How the three spring months (March, April and May) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 28° / 14° | 1.8 | 7.7 | 6.4 | 9.2 | 0.0 |
| Feb | 32° / 17° | 1.7 | 6.9 | 5.5 | 10.3 | 0.0 |
| Mar | 44° / 28° | 2.4 | 9.4 | 3.5 | 11.6 | 1.0 |
| Apr | 57° / 39° | 4.0 | 12 | 1.6 | 13.1 | 3.7 |
| May | 68° / 50° | 3.9 | 12.2 | 0.1 | 14.4 | 5.9 |
| Jun | 78° / 60° | 4.1 | 11.6 | 0 | 15.1 | 6.4 |
| Jul | 81° / 64° | 3.3 | 10.1 | 0 | 14.8 | 6.5 |
| Aug | 79° / 62° | 3.6 | 10.3 | 0 | 13.7 | 6.7 |
| Sep | 72° / 54° | 3.3 | 8.8 | 0 | 12.3 | 6.9 |
| Oct | 59° / 42° | 2.8 | 8.9 | 0.3 | 10.8 | 4.8 |
| Nov | 45° / 31° | 2.2 | 8 | 2 | 9.6 | 1.1 |
| Dec | 33° / 20° | 2.0 | 7.8 | 5 | 8.9 | 0.0 |
Cloud cover in Spring
The sky is clear or mostly clear about 23% of the time across spring.
Chance of precipitation in Spring
Janesville gets around 10.3 in of rain and snow over 34 wet days across spring. The line is the day-by-day chance of measurable precipitation.
Humidity in Spring
Most of spring feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Spring
Winds average 8 mph across spring.
Sunrise & sunset in Spring
Daylight runs from about 10 h 54 min in early March to 14 h 54 min by late May. The lit band spans sunrise to sunset each day.
Solar energy in Spring
Average shortwave solar energy reaching the ground each day across spring, about 4.9 kWh/m².
Is spring a good time to visit Janesville?
Our two travel scores rate spring for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
spring is a weaker month for outdoor sightseeing in Janesville.
What to pack for Janesville in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, Janesville sees daytime highs around 56°F and nights near 39°F. Pack a warm layer and a heavy coat. Worth having: rain gear and sun protection. About 34 days see rain.
UV index in Janesville in Spring
Clear-sky midday UV across spring averages around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Janesville peaks around June 19 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 4 | 6 | 8 | 9 | 8 | 8 | 6 | 3 | 2 | 1 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 4 | Moderate |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 8 | Very high |
| Aug | 8 | Very high |
| Sep | 6 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Moderate |
| Dec | 1 | Low |
Air quality in Janesville in Spring
Average fine-particle pollution (PM2.5) through the year — so you can see where spring falls, not just the annual average.
Air quality in Janesville is worst in July — around 15 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (October, 8 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 11 | 13 | 13 | 12 | 13 | 14 | 15 | 14 | 11 | 8 | 8 | 9 |
| Level | Good | Moderate | Moderate | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 11 | Good |
| Feb | 13 | Moderate |
| Mar | 13 | Moderate |
| Apr | 12 | Good |
| May | 13 | Moderate |
| Jun | 14 | Moderate |
| Jul | 15 | Moderate |
| Aug | 14 | Moderate |
| Sep | 11 | Good |
| Oct | 8 | Good |
| Nov | 8 | Good |
| Dec | 9 | Good |
Where is Janesville?
Janesville sits at 42.7°N, 89.0°W, 837 ft above sea level, in United States. The nearest listed city is Beloit, 12 mi away.
Topography around Janesville
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Janesville.
Within 2 miles, the terrain around Janesville has only modest variations in elevation — a maximum elevation change of 200 ft around an average of 833 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 348 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,063 ft.
The land around Janesville is covered by artificial surfaces (37%), trees (34%) and grassland (22%) within 2 miles, cropland (58%) within 10 miles, and cropland (56%) and trees (22%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Janesville (42.6828°, -89.0187°, elevation 837 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.