Portland (ME)
May
Weather in Portland, Maine for May 2026
Your guide to Portland weather in May - trends and predictions
In general, the average temperature in Portland at the beginning of May is 11.9 °F. As the month progressed, temperatures tended to significantly warm up, reaching an average of 16.6 °F by the end of May.
Portland in May brings notable rainfall, with an average of 17 rainy days and a total precipitation of 248 mm.
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Temperatures
Rain 🌧️
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14
Dry days
17
Rainy days
0
Snow days
14°/9°
Temperatures
17 km/h
Avg max wind
81 %
Avg humidity
Portland Weather May
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Temperatures trend during May in Portland
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May weather in Portland day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| May 1 |  Patchy rain possible | 11° /5° | 0.8 mm | 3 | |
| May 2 | Light rain shower | 11° /7° | 1.6 mm | 3 | |
| May 3 | Patchy rain possible | 13° /7° | 1.4 mm | 3 | |
| May 4 |  Overcast | 11° /8° | 0 mm | 3 | |
| May 5 |  Light rain | 10° /6° | 6.8 mm | 3 | |
| May 6 |  Fog | 12° /7° | 45.8 mm | 3 | |
| May 7 |  Partly cloudy | 15° /8° | 9.9 mm | 4 | |
| May 8 | Light rain shower | 12° /8° | 4.7 mm | 3 | |
| May 9 | Light drizzle | 10° /6° | 6.9 mm | 3 | |
| May 10 | Patchy rain possible | 10° /6° | 19.6 mm | 3 | |
| May 11 | Patchy rain possible | 13° /7° | 0 mm | 4 | |
| May 12 | Light rain shower | 12° /6° | 0.3 mm | 4 | |
| May 13 | Patchy rain possible | 12° /7° | 1.1 mm | 3 | |
| May 14 |  Moderate or heavy rain shower | 15° /8° | 5.5 mm | 4 | |
| May 15 | Light drizzle | 15° /10° | 0.7 mm | 4 | |
| May 16 | Patchy rain possible | 15° /10° | 0.1 mm | 4 | |
| May 17 | Patchy rain possible | 13° /9° | 1.2 mm | 4 | |
| May 18 | Partly cloudy | 15° /9° | 0 mm | 5 | |
| May 19 | Patchy rain possible | 14° /8° | 0.1 mm | 4 | |
| May 20 | Partly cloudy | 14° /7° | 0 mm | 4 | |
| May 21 | Mist | 15° /8° | 0 mm | 4 | |
| May 22 | Fog | 18° /10° | 39.7 mm | 4 | |
| May 23 | Light rain shower | 16° /10° | 39.4 mm | 4 | |
| May 24 | Partly cloudy | 17° /10° | 0 mm | 4 | |
| May 25 |  Sunny | 16° /8° | 0 mm | 4 | |
| May 26 | Patchy rain possible | 17° /10° | 0.4 mm | 5 | |
| May 27 | Light rain shower | 15° /10° | 9.2 mm | 4 | |
| May 28 | Fog | 19° /12° | 2.5 mm | 5 | |
| May 29 | Light rain shower | 16° /11° | 14 mm | 4 | |
| May 30 | Partly cloudy | 17° /9° | 0 mm | 4 | |
| May 31 | Partly cloudy | 16° /10° | 36.2 mm | 4 | |
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Important Notice
Our weather forecast for Portland in May is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Portland forecast closer to your planned date for the most up-to-date weather information.
Change Month
Portland in May - FAQ
What are the expected maximum and minimum temperatures in Portland during May?
During May, expect a variety of temperatures with highs around 14° and lows near 9°, suitable for diverse activities and preferences.
How much rainfall should be expected in Portland during May?
Significant rainfall exceeding 248 mm is expected in Portland during May, occurring over more than 17 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Portland during May?
The average wind speed in Portland during May is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
May rainfall patterns in Portland
Explore the daily rainfall trends and prepare for Portlands May weather 💧
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