United States Boston Weather in May — Climate Guide
May in Boston is very-high
May is very-high for Boston.
May is graduation surge month — Harvard graduation Commencement (mid-May Thu/Fri), MIT graduation Commencement (mid-May), Boston University + Northeastern + Boston College all graduate within a 2-week window. Cambridge hotels (Charles Hotel + Boston Marriott Cambridge + Sheraton Commander) all sell out 4-6 months ahead.
Weather hits the spring sweet spot — 20°C / 68°F days, 10°C / 50°F nights, low humidity. Cherry blossoms + magnolias peak early-mid May. Boston Public Garden tulips + lilacs peak. Charles River Esplanade ideal walking + biking.
Travel score
Boston May Weather Stats
Avg High
20°C
Avg Low
10°C
Rainy Days
11
90mm total
Sunshine
9h
Daily avg
Humidity
60%
moderate
UV Index
7
High
Wind
14 km/h
Gusts 35
Sea Temp
11°C
swimming chilly
Crowds
Very busy
At attractions
May Sunrise & Sunset
Air Quality
PM2.5
7 μg/m³
PM10
17 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
21°C
Nighttime
11°C
Humidity and wind affect how the actual temperature feels.
Wind
14 km/h
Max gust 35 km/h
Activities Recommended for May
May Travel Pros & Cons
Pros
- Ideal spring weather 20°C / 68°F days
- Cherry blossoms + magnolias + tulips peak
- Lilac Sunday Arnold Arboretum (free, 300+ varieties)
- Fenway Park Red Sox season in full swing
Cons
- Graduation weekends hotel surge
- Memorial Day weekend surge
- Pre-summer humidity rising
- Mother's Day brunch reservations difficult
May Events & Festivals
- Harvard graduation Commencement (mid-May, Thu/Fri)
- MIT graduation Commencement (mid-May)
- Boston University + Northeastern graduations
- Memorial Day weekend (last Mon May)
- Lilac Sunday Arnold Arboretum (mid-May)
Boston in May — Full Picture
May is graduation surge month — Harvard graduation Commencement (mid-May Thu/Fri), MIT graduation Commencement (mid-May), Boston University + Northeastern + Boston College all graduate within a 2-week window. Cambridge hotels (Charles Hotel + Boston Marriott Cambridge + Sheraton Commander) all sell out 4-6 months ahead.
Weather hits the spring sweet spot — 20°C / 68°F days, 10°C / 50°F nights, low humidity. Cherry blossoms + magnolias peak early-mid May. Boston Public Garden tulips + lilacs peak. Charles River Esplanade ideal walking + biking.
Memorial Day weekend (last Monday May) kicks off the American summer travel season. Hotels add 30-50% surge for the holiday weekend.
The Lilac Sunday at Arnold Arboretum (Harvard's arboretum in Jamaica Plain, mid-May, free) is the canonical Boston spring flowers event — 300+ lilac varieties + free Park Ranger tours + jazz performances. Mother's Day weekend (2nd Sunday May) brings brunch peak — Tatte Bakery + Mistral + Henrietta's Table all reserve solid.
Fenway Park is in full swing — Red Sox home games are the canonical May Boston activity. The smart May move: target the first 2 weeks (pre-graduation, pre-Memorial Day) for the spring shoulder pricing window.
What to Wear & What to Pack
Spring ideal — light jacket morning/evening + t-shirt + jeans by day. Late spring foliage + Boston Public Garden tulips peak early May. Graduation weekends drive hotel surges.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current14°C
4.3°C
11.7/mo
Summer (Jun·Jul·Aug)
26.7°C
17.3°C
9.7/mo
Autumn (Sep·Oct·Nov)
17°C
8.3°C
9.7/mo
Winter (Dec·Jan·Feb)
3.7°C
-4.7°C
11/mo
Boston Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 2° | -6° | 11d·90mm | 5h | 65% | 2 | Quiet | Low season | |
| 4° | -5° | 10d·80mm | 6h | 64% | 3 | Quiet | Low season | |
| 8° | -1° | 12d·95mm | 7h | 62% | 4 | Quiet | Low season | |
| 14° | 4° | 12d·95mm | 8h | 60% | 5 | Very busy | Peak | |
| May (Best) | 20° | 10° | 11d·90mm | 9h | 60% | 7 | Very busy | Peak |
| June (Best) | 25° | 15° | 11d·90mm | 10h | 64% | 9 | Busy | Peak |
| July (Best) | 28° | 19° | 9d·85mm | 11h | 67% | 10 | Very busy | Peak |
| August (Best) | 27° | 18° | 9d·90mm | 10h | 70% | 9 | Very busy | Peak |
| September (Best) | 23° | 14° | 9d·90mm | 9h | 65% | 7 | Very busy | Peak |
| October (Best) | 17° | 8° | 9d·95mm | 7h | 65% | 5 | Very busy | Peak |
| 11° | 3° | 11d·95mm | 5h | 65% | 3 | Busy | Peak | |
| 5° | -3° | 12d·100mm | 5h | 65% | 2 | Very busy | Peak |
View Other Months
Boston May Hotel Picks
Frequently Asked Questions
Is May a good time to visit Boston?
Boston in May is very-high. Tourist crowds are very busy and flight/hotel prices are peak.
What's the average temperature in Boston in May?
Boston May averages a high of 20°C and a low of 10°C.
Does it rain much in Boston in May?
Boston May averages 90mm of rainfall over about 11 rainy days.
What should I wear in Boston in May?
Spring ideal — light jacket morning/evening + t-shirt + jeans by day. Late spring foliage + Boston Public Garden tulips peak early May. Graduation weekends drive hotel surges.
What time are sunrise and sunset in Boston in May?
Boston May sunrise is 05:30 and sunset is 20:00, with 14h 30m of daylight.
What's the air quality like in Boston in May?
Boston May air quality (AQI) averages 28, rated Good. PM2.5 averages 7μg/m³.
What activities are recommended in Boston in May?
In May, Boston is great for Boston Public Garden Swan Boats + tulips, Lilac Sunday Arnold Arboretum (free), Fenway Park Red Sox home games.
Is May peak season in Boston?
Boston May crowds are very busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Boston
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.