Johnston in Winter
In winter (December, January and February), Johnston sees average daytime highs around 33°F and overnight lows near 17°F, with 4.2 in of precipitation over about 19 wet days across the season. It is the coldest season of the year and the driest season of the year.
Across winter, daytime highs hold fairly steady around 33°F. The sky is clear or mostly clear about 28% of the time across winter, and the air most often feels dry.
Winter is Johnston's weakest season of the year to visit on our travel score. For the whole year in context, see Johnston's year-round climate.
- Avg daytime high
- 33°F
- coldest season of the year
- Avg overnight low
- 17°F
- Precipitation
- 4.2 in
- 19 wet days
- Avg wind
- 9 mph
- Travel score
- 0.0
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Johnston in Winter
Across winter, daytime highs hold fairly steady around 33°F.
A typical winter day in Johnston reaches about 33°F and drops to 17°F overnight. The warmest of the three months is December, the coolest January.
How winter really feels in Johnston
Once humidity and wind are folded in, winter brings about 0 days that feel above 90°F and 90 that feel at or below 32°F.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Johnston weather by month
How the three winter months (December, January and February) 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 | 29° / 13° | 1.2 | 6.2 | 4.9 | 9.3 | 0.0 |
| Feb | 34° / 17° | 1.4 | 6.5 | 4.8 | 10.3 | 0.0 |
| Mar | 48° / 29° | 2.6 | 8.8 | 2.8 | 11.7 | 1.7 |
| Apr | 61° / 40° | 4.3 | 11.1 | 1 | 13.1 | 4.7 |
| May | 71° / 52° | 5.5 | 13.7 | 0.1 | 14.3 | 6.0 |
| Jun | 80° / 62° | 5.0 | 12.1 | 0 | 15 | 6.1 |
| Jul | 84° / 66° | 3.7 | 9.5 | 0 | 14.7 | 5.8 |
| Aug | 82° / 63° | 3.9 | 9.2 | 0 | 13.7 | 6.6 |
| Sep | 75° / 55° | 3.4 | 8.6 | 0 | 12.3 | 7.2 |
| Oct | 62° / 42° | 2.9 | 8 | 0.4 | 10.9 | 5.7 |
| Nov | 47° / 30° | 2.1 | 6.5 | 1.3 | 9.6 | 1.8 |
| Dec | 35° / 19° | 1.6 | 6 | 4.1 | 9 | 0.0 |
Cloud cover in Winter
The sky is clear or mostly clear about 28% of the time across winter.
Chance of precipitation in Winter
Johnston gets around 4.2 in of rain and snow over 19 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 9 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 12 min in early December to 10 h 54 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.4 kWh/m².
Is winter a good time to visit Johnston?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Johnston.
What to pack for Johnston in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Johnston sees daytime highs around 33°F and nights near 17°F. Pack a warm layer and a heavy coat. About 19 days see rain.
UV index in Johnston in Winter
Clear-sky midday UV across winter averages around 2. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Johnston peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (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 | 7 | 9 | 9 | 7 | 6 | 4 | 3 | 2 |
| Level | Low | Moderate | Moderate | High | 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 | 7 | High |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 7 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Johnston in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Johnston is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 7 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) | 13 | 15 | 14 | 11 | 11 | 12 | 16 | 14 | 12 | 7 | 9 | 10 |
| Level | Moderate | Moderate | Moderate | Good | Good | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 15 | Moderate |
| Mar | 14 | Moderate |
| Apr | 11 | Good |
| May | 11 | Good |
| Jun | 12 | Moderate |
| Jul | 16 | Moderate |
| Aug | 14 | Moderate |
| Sep | 12 | Good |
| Oct | 7 | Good |
| Nov | 9 | Good |
| Dec | 10 | Good |
Where is Johnston?
Johnston sits at 41.7°N, 93.7°W, 830 ft above sea level, in United States. The nearest listed city is Urbandale, 3.1 mi away.
Topography around Johnston
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Johnston.
Within 2 miles, the terrain around Johnston has only modest variations in elevation — a maximum elevation change of 217 ft around an average of 846 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 305 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 787 ft.
The land around Johnston is covered by trees (40%) and grassland (26%) within 2 miles, trees (29%), cropland (25%) and grassland (22%) within 10 miles, and cropland (65%) 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 Johnston (41.673°, -93.6977°, elevation 830 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.