Boston in May
In May, Boston averages 19°C (66°F) during the day and 9°C (48°F) at night, with around 11 days of rain (88 mm total).
High seasonConditions are comfortable for sightseeing without being sweltering. Plan for unsettled weather and bring rain gear.
May offers comfortable temperatures in Boston, with some rain to plan around.
How May compares to the rest of the year in Boston
May is in the middle of the year for warmth in Boston (5th of 12) and moderately rainy compared to the rest of the year (4th of 12). Daytime temperature runs 4°C above the annual average (15°C). May runs 5°C warmer than April (14°C) and warms a further 6°C into June (25°C).
May sunrise & sunset in Boston
Times shown for Boston local time (America/New_York), calculated for the 15th of May. They shift by a few minutes day to day across the month.
Photography light in Boston — May
Golden-hour and blue-hour windows for the 15th of May, in Boston's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — Boston in May
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on May's tier (High season) and Boston's popularity.
Crowds & pricing — May in Boston
This is a busy month in Boston — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.
Why this tier: excellent tourism weather
Sun & mosquito risk — May in Boston
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
📊 Right now vs typical — Boston in May
The past 30 days in Boston have been running 2.7°C warmer than the typical May average.
Comparison window 2026-05-09 → 2026-06-08 (23 days of observed data). Single-month windows are noisy — strong signals here flag a real anomaly; small ones (<1°C) are within typical year-to-year variation.
Sea temperature in Boston — May
Across the year Boston's sea swings from 3.5°C (February) to 19.6°C (August) — May sits at 13.2°C.
Boston in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 2°C / 36°F | -6°C / 21°F | 88 mm | 10 | 10 |
| February | 3°C / 37°F | -5°C / 23°F | 88 mm | 10 | 9 |
| March | 7°C / 45°F | -1°C / 30°F | 104 mm | 11 | 5 |
| April | 14°C / 57°F | 4°C / 39°F | 92 mm | 11 | 1 |
| May | 19°C / 66°F | 9°C / 48°F | 88 mm | 11 | 0 |
| June | 25°C / 77°F | 15°C / 59°F | 95 mm | 11 | 0 |
| July | 28°C / 82°F | 18°C / 64°F | 84 mm | 9 | 0 |
| August | 27°C / 81°F | 17°C / 63°F | 94 mm | 9 | 0 |
| September | 23°C / 73°F | 13°C / 55°F | 85 mm | 9 | 0 |
| October | 17°C / 63°F | 7°C / 45°F | 96 mm | 10 | 0 |
| November | 11°C / 52°F | 2°C / 36°F | 108 mm | 11 | 1 |
| December | 5°C / 41°F | -3°C / 27°F | 106 mm | 12 | 7 |
Other cities with similar May weather
🌍 See the full ranked list of climate twins for Boston in May →
Frequently asked questions
How hot is Boston in May?
In May, Boston averages a high of 19°C (66°F) and a low of 9°C (48°F) — generally mild and pleasant.
Does it rain a lot in Boston in May?
May can be fairly wet in Boston, with about 11 rainy days on average.
Is May a good time to visit Boston?
May is mild and pleasant. It suits travelers who are comfortable with mild and pleasant weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for Boston in May?
Pack light layers for warm days and cooler evenings, plus a compact umbrella or rain jacket. See the full May packing list for Boston for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.