Union City in Spring
In spring (March, April and May), Union City sees average daytime highs around 66°F and overnight lows near 49°F, with 5.3 in of rain over about 18 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs climb from about 60°F in early March to 72°F by late May. The sky is clear or mostly clear about 46% of the time across spring, and the air most often feels dry.
Spring is Union City's 3rd-best season to visit on our travel score. For the whole year in context, see Union City's year-round climate.
- Avg daytime high
- 66°F
- 3rd-warmest season
- Avg overnight low
- 49°F
- Rainfall
- 5.3 in
- 18 wet days
- Avg wind
- 5 mph
- Travel score
- 6.8
- 3rd-best season
- Months
- Mar · Apr · May
Temperature in Union City in Spring
Over the season highs climb from about 60°F in early March to 72°F by late May.
A typical spring day in Union City reaches about 66°F and drops to 49°F overnight. The warmest of the three months is May, the coolest March.
Union City 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 | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 57° / 43° | 3.6 | 8.9 | 9.7 | 4.2 |
| Feb | 59° / 45° | 3.8 | 8.9 | 10.6 | 4.7 |
| Mar | 62° / 47° | 2.9 | 9.1 | 11.7 | 5.6 |
| Apr | 65° / 48° | 1.6 | 5.7 | 12.9 | 6.8 |
| May | 70° / 52° | 0.8 | 3.4 | 14 | 7.9 |
| Jun | 76° / 55° | 0.2 | 0.9 | 14.5 | 9.1 |
| Jul | 80° / 58° | 0.0 | 0.2 | 14.3 | 9.0 |
| Aug | 81° / 59° | 0.0 | 0.2 | 13.4 | 8.9 |
| Sep | 79° / 58° | 0.1 | 0.4 | 12.3 | 9.0 |
| Oct | 73° / 54° | 0.9 | 2.9 | 11 | 8.5 |
| Nov | 63° / 48° | 1.7 | 5.7 | 10 | 6.3 |
| Dec | 57° / 43° | 3.3 | 8.9 | 9.5 | 4.2 |
Cloud cover in Spring
The sky is clear or mostly clear about 46% of the time across spring.
Chance of precipitation in Spring
Union City gets around 5.3 in of rain over 18 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 5 mph across spring.
Sunrise & sunset in Spring
Daylight runs from about 11 h 06 min in early March to 14 h 24 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 6.1 kWh/m².
Is spring a good time to visit Union City?
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 reasonable time to visit Union City for sightseeing.
What to pack for Union City in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, Union City sees daytime highs around 66°F and nights near 49°F. Pack sun protection. Worth having: a warm layer and rain gear. About 18 days see rain.
Sea temperature near Union City in Spring
The nearest coast averages about 54°F across spring — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 25 mi away) is warmest in August at about 59°F and coldest in April near 54°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 54 | 54 | 54 | 54 | 54 | 55 | 57 | 59 | 59 | 58 | 56 | 55 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 54 | Bracing |
| Feb | 54 | Bracing |
| Mar | 54 | Bracing |
| Apr | 54 | Bracing |
| May | 54 | Bracing |
| Jun | 55 | Bracing |
| Jul | 57 | Bracing |
| Aug | 59 | Bracing |
| Sep | 59 | Bracing |
| Oct | 58 | Bracing |
| Nov | 56 | Bracing |
| Dec | 55 | Bracing |
UV index in Union City 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 Union City peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 5 | 7 | 8 | 10 | 10 | 10 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Extreme | Extreme | Very high | High | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | Moderate |
| Apr | 7 | High |
| May | 8 | Very high |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 10 | Very high |
| Sep | 6 | High |
| Oct | 5 | High |
| Nov | 2 | Moderate |
| Dec | 2 | Moderate |
Air quality in Union City 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 Union City is worst in August — around 25 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (June, 10 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) | 15 | 18 | 16 | 12 | 10 | 10 | 11 | 25 | 17 | 20 | 18 | 13 |
| Level | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 15 | Moderate |
| Feb | 18 | Moderate |
| Mar | 16 | Moderate |
| Apr | 12 | Moderate |
| May | 10 | Good |
| Jun | 10 | Good |
| Jul | 11 | Good |
| Aug | 25 | Moderate |
| Sep | 17 | Moderate |
| Oct | 20 | Moderate |
| Nov | 18 | Moderate |
| Dec | 13 | Moderate |
Where is Union City?
Union City sits at 37.6°N, 122.0°W, 69 ft above sea level, in United States. The nearest listed city is Fremont, 3.7 mi away.
Topography around Union City
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Union City.
Within 2 miles, the terrain around Union City has significant variations in elevation — a maximum elevation change of 1,096 ft around an average of 190 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,625 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.
The land around Union City is covered by artificial surfaces (51%) and grassland (29%) within 2 miles, artificial surfaces (28%), grassland (24%) and water (23%) within 10 miles, and water (28%), grassland (26%) and trees (25%) 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 Union City (37.5958°, -122.0191°, elevation 69 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.