Monthly weather averages & travel planning

North America › 🇺🇸 United States › Boston
Updated: March 2026
April is a good time to visit Boston (6/10). Average highs of 19°C and 6 sunshine hours daily make conditions workable, though not exceptional. Culture-focused travellers and those who prefer lighter crowds will find April a practical choice, with prices running lower than peak May without sacrificing all the good weather. May offers a similar profile at lower hotel rates if dates are flexible. The main practical note: Boston's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: accommodation is generally available without long lead times, and flight prices are typically lower than peak season. Flexible travellers will find the best deals by booking 2-4 weeks ahead. Mid-week arrivals consistently unlock lower hotel rates than weekend check-ins.
Boston's April weather is shaped by atmospheric forces that make the data more than just numbers. The 19°C average high reflects a transitional pressure pattern where mid-latitude westerlies alternately bring mild maritime air and cooler polar intrusions. As a result, 6 daily sunshine hours are recorded on average, and rainfall of 60mm is distributed across approximately 5 days because precipitation events tend to be brief and infrequent.
19°C
66°F
Avg High
7°C
45°F
Avg Low
5 days
60 mm total
Rain Days
6h
per day avg
Sunshine
65%
Moderate
Humidity
The 12°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. Humidity averages 65%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. UV index averages 6 this month, classed as moderate. Sunscreen is a sensible precaution for extended outdoor time, particularly at midday. Wind averages 15 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 66°F average high, 45°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Packing for Boston in April means dressing for 19°C days and 7°C evenings. A light cotton tee with a casual overshirt works well at 19°C, the overshirt doubles as a layer for air-conditioned venues. Evenings drop 12°C to around 7°C, a notable shift that catches underprepared visitors off guard. Pack a dedicated evening layer. Comfortable walking trainers are the versatile choice for both outdoor sightseeing and indoor venues.
Local tip: Layers are more practical than a single heavy garment in Boston. The day-to-evening temperature shift rewards packing a versatile mid-layer you can add or remove as conditions change.
April has no major festivals or public holidays in Boston, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
Based on 19°C average highs and 5 rainy days
April marks the transition into warmer conditions in Boston, as the sun angle climbs and day length extends. Temperatures averaging 19°C by day and 7°C overnight reflect a city shaking off winter: the morning air still carries a cool edge, but afternoons are noticeably warmer than even four weeks prior. At 42 degrees north latitude, spring is one of the most dynamic periods in the annual cycle, with weekly temperature changes that can be larger than the month-to-month shifts of summer. This volatility is part of the appeal: Boston in April has a freshness and energy that peak-summer heat tends to mute. Layers remain essential, but there are reliable pockets of warmth that reward patience. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
Boston in April
April ranks 4th sunniest of the year in Boston, with an average 6 daily sunshine hours. The driest months are January, February, and October. June is the hottest month (24°C avg high); December is the coolest (3°C). From here, temperatures rise 3°C into May. Compared to last month (March: 13°C high, 4 rain days), April is warmer and wetter. April sits in the middle of the annual sunshine ranking for Boston, offering a reasonable balance of good weather and manageable crowds.
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 4°C | -8°C | 3 | 1h | View |
| February | 8°C | -4°C | 3 | 3h | View |
| March | 13°C | 1°C | 4 | 4h | View |
| April | 19°C | 7°C | 5 | 6h | View |
| May | 22°C | 10°C | 6 | 7h | View |
| June | 24°C | 12°C | 6 | 7h | View |
| July | 22°C | 10°C | 6 | 7h | View |
| August | 19°C | 7°C | 5 | 6h | View |
| September | 13°C | 1°C | 4 | 4h | View |
| October | 8°C | -4°C | 3 | 3h | View |
| November | 4°C | -8°C | 3 | 1h | View |
| December | 3°C | -9°C | 3 | 1h | View |
January
3 rain days, 1h sun
February
3 rain days, 3h sun
March
4 rain days, 4h sun
April
5 rain days, 6h sun
May
6 rain days, 7h sun
June
6 rain days, 7h sun
July
6 rain days, 7h sun
August
5 rain days, 6h sun
September
4 rain days, 4h sun
October
3 rain days, 3h sun
November
3 rain days, 1h sun
December
3 rain days, 1h sun
Cities within 500 km with comparable weather conditions
Data Sources for Boston
Climate normals represent 30-year averages (1991-2020). Individual years may vary.