South Portland in Spring
In spring (March, April and May), South Portland sees average daytime highs around 47°F and overnight lows near 38°F, with 13.2 in of precipitation over about 33 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs climb from about 36°F in early March to 60°F by late May. The sky is clear or mostly clear about 27% of the time across spring, and the air most often feels dry.
Spring is South Portland's 3rd-best season to visit on our travel score. For the whole year in context, see South Portland's year-round climate.
- Avg daytime high
- 47°F
- 3rd-warmest season
- Avg overnight low
- 38°F
- Precipitation
- 13.2 in
- 33 wet days
- Avg wind
- 10 mph
- Travel score
- 1.8
- 3rd-best season
- Months
- Mar · Apr · May
Temperature in South Portland in Spring
Over the season highs climb from about 36°F in early March to 60°F by late May.
A typical spring day in South Portland reaches about 47°F and drops to 38°F overnight. The warmest of the three months is May, the coolest March.
How spring really feels in South Portland
Once humidity and wind are folded in, spring brings about 0 days that feel above 90°F and 47 that feel at or below 32°F.
The story in spring is cold — wind chill drags the overnight "feels like" below the raw low.
South Portland 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 | 32° / 20° | 3.9 | 9.9 | 6.9 | 9.1 | 0.0 |
| Feb | 33° / 21° | 3.6 | 8.9 | 6.5 | 10.2 | 0.0 |
| Mar | 38° / 28° | 4.6 | 10.9 | 5.6 | 11.6 | 0.0 |
| Apr | 47° / 38° | 4.7 | 10.7 | 1.9 | 13.2 | 1.6 |
| May | 56° / 47° | 3.9 | 11 | 0.1 | 14.5 | 3.7 |
| Jun | 65° / 56° | 4.0 | 10.3 | 0 | 15.2 | 5.7 |
| Jul | 71° / 63° | 3.1 | 9.2 | 0 | 14.9 | 6.7 |
| Aug | 71° / 63° | 3.2 | 8.4 | 0 | 13.8 | 6.9 |
| Sep | 65° / 57° | 3.7 | 8.7 | 0 | 12.3 | 6.2 |
| Oct | 56° / 47° | 5.4 | 10.6 | 0.2 | 10.8 | 3.8 |
| Nov | 46° / 37° | 4.5 | 10.4 | 1.4 | 9.5 | 1.3 |
| Dec | 37° / 28° | 4.9 | 11 | 5.8 | 8.8 | 0.0 |
Cloud cover in Spring
The sky is clear or mostly clear about 27% of the time across spring.
Chance of precipitation in Spring
South Portland gets around 13.2 in of rain and snow over 33 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 10 mph across spring.
Sunrise & sunset in Spring
Daylight runs from about 10 h 54 min in early March to 15 hours 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 4.8 kWh/m².
Hazard calendar for South Portland
None of South Portland's seasonal hazards peak in spring. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do.
South Portland sits in the Atlantic hurricane belt; the season peaks August–October.
Is spring a good time to visit South Portland?
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 South Portland.
What to pack for South Portland in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, South Portland sees daytime highs around 47°F and nights near 38°F. Pack a warm layer and a heavy coat. Worth having: rain gear and sun protection. About 33 days see rain.
Sea temperature near South Portland in Spring
The nearest coast averages about 43°F across spring — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 63°F and coldest in March near 38°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) | 42 | 39 | 38 | 42 | 48 | 55 | 62 | 63 | 60 | 54 | 49 | 45 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 42 | Bracing |
| Feb | 39 | Bracing |
| Mar | 38 | Bracing |
| Apr | 42 | Bracing |
| May | 48 | Bracing |
| Jun | 55 | Bracing |
| Jul | 62 | Cool |
| Aug | 63 | Cool |
| Sep | 60 | Cool |
| Oct | 54 | Bracing |
| Nov | 49 | Bracing |
| Dec | 45 | Bracing |
UV index in South Portland in Spring
Clear-sky midday UV across spring averages around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in South Portland peaks around July 12 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 23 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 5 | 7 | 7 | 7 | 4 | 6 | 3 | 2 | 1 |
| Level | Low | Moderate | Moderate | Moderate | High | High | Very high | Moderate | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Moderate |
| Mar | 4 | Moderate |
| Apr | 5 | Moderate |
| May | 7 | High |
| Jun | 7 | High |
| Jul | 7 | Very high |
| Aug | 4 | Moderate |
| Sep | 6 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Where is South Portland?
South Portland sits at 43.6°N, 70.2°W, 23 ft above sea level, in United States. The nearest listed city is Portland, 1.2 mi away.
Topography around South Portland
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of South Portland.
Within 2 miles, the terrain around South Portland has only modest variations in elevation — a maximum elevation change of 207 ft around an average of 46 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 548 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,182 ft.
The land around South Portland is covered by water (36%), trees (32%) and artificial surfaces (22%) within 2 miles, water (48%) and trees (37%) within 10 miles, and trees (60%) and water (34%) 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 South Portland (43.6415°, -70.2409°, elevation 23 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.