Boston, September 15, 2025
News Summary
Boston is set to enjoy warm and mostly dry weather throughout the upcoming week. Daytime temperatures will primarily hover in the mid-70s, with a warm-up to the low 80s by Friday. Humidity will remain comfortable, and only minimal precipitation is expected late Wednesday into Thursday. As autumn approaches, the weekend will bring seasonal cooling, keeping outdoor conditions favorable for residents and visitors alike.
Boston
Warm and mostly dry weather is expected across Boston for the upcoming week, with daytime temperatures generally in the mid-70s early in the week and a brief warm-up into the low 80s by Friday. Overall conditions will be pleasant, with comfortable humidity, limited precipitation, and seasonal cooling by the following weekend as autumn approaches.
Key details
The week begins with sunny skies and highs in the mid-70s on Monday, followed by similar conditions on Tuesday and Wednesday. Nighttime temperatures will be cooler, dropping into the mid-50s Monday night. Winds are expected to be light, and dew points at or below 60 degrees will keep the air comfortable through the week.
Late Wednesday night into Thursday morning brings an increased cloud deck and a 30 percent chance of rain starting after 3 a.m. on Thursday. Any precipitation is expected to be minimal and most likely to affect the Cape and Islands. Thursday daytime highs may reach the upper 70s with a mix of sun and clouds, and Friday is forecast to be the warmest day of the stretch with highs into the low 80s under mostly sunny skies.
Day-by-day forecast (high-level)
Monday
Sunny, highs in the mid-70s; lows Monday night in the mid-50s. Morning fog possible early, burning off to sun.
Tuesday–Wednesday
Mostly sunny, highs remaining in the mid-70s. Calm winds and comfortable dew points near or below 60.
Wednesday night–Thursday
Clouds increase overnight. A 30 percent chance of light rain begins after 3 a.m. Thursday and could persist through the day, with the highest impact concentrated on the Cape and Islands. Precipitation is expected to be limited overall.
Thursday
Partly sunny with highs in the upper 70s; isolated light showers most likely around the Cape and Islands.
Friday
Mostly sunny and warmer, with highs into the low 80s.
Weekend
Temperatures cool to the upper 60s for highs with mostly sunny, dry conditions expected. Southeastern Massachusetts may see isolated showers over the weekend, but no severe weather is anticipated.
Regional differences
- Cape and Islands: Morning fog likely early in the week, then low 70s in the afternoons after fog clears. Small chance for light, localized rain around Thursday.
- Central and Western Massachusetts: Expect highs in the upper 70s to around 80 by Tuesday with generally sunny skies.
- Southeastern Massachusetts: Slightly higher chance of isolated showers over the weekend, but precipitation is expected to remain light.
Why this matters
September in this region is typically comfortable, and the upcoming week reflects that pattern: temperatures that usually do not require continuous air conditioning, low humidity levels, and pleasant daytime conditions that are good for outdoor activities. Light overnight cooling will require a light jacket for some, especially early in the week.
Seasonal notes
The final week of astronomical summer begins this period, with autumn arriving on Monday, September 22 at 2:19 p.m. This week also features the greatest daily loss of daylight for the year in this area, with nearly three minutes less daylight each day. Those changes will contribute to the noticeable cooling trend by next weekend.
Preparedness and impact
No severe weather is expected this week. Residents and visitors should monitor localized conditions if traveling to the Cape and Islands before Thursday, as isolated light showers are possible. Otherwise, planned outdoor events and activities are unlikely to be significantly affected by weather during most of the week.
Frequently Asked Questions
Will I need air conditioning this week?
Most days will be comfortable with highs in the mid-70s to low 80s and dew points at or below 60. Air conditioning will likely not be needed continuously, though individual comfort varies and occasional use on the warmest day (Friday) is possible.
Is significant rain expected?
No. There is a limited chance of light rain beginning after 3 a.m. Thursday, mostly affecting the Cape and Islands. Any rainfall is expected to be minimal.
Will humidity be high?
Humidity is expected to be low to moderate, with dew points around or below 60 degrees, which should feel comfortable for most people.
When does fall officially start this year?
Astronomical autumn begins on Monday, September 22 at 2:19 p.m.
Are there any travel impacts expected?
Travel impacts are expected to be minimal. The only potential issue could be localized fog early in the week or an isolated, light shower near the Cape and Islands around Thursday.
Weekly quick-reference table
| Day | Expected Highs | Sky/Conditions | Rain Chance | Notes |
|---|---|---|---|---|
| Monday | Mid-70s | Sunny; morning fog possible | Minimal | Cool night—mid-50s |
| Tuesday | Mid-70s | Mostly sunny | Low | Comfortable dew points |
| Wednesday | Mid-70s | Mostly sunny | Low | Clouds increase late |
| Thursday | Upper 70s | Partly sunny to mostly cloudy | 30% (after 3 a.m.) | Light, isolated rain mainly on Cape/Islands |
| Friday | Low 80s | Sunny | Minimal | Warmest day |
| Weekend | Upper 60s | Mostly sunny, dry | Low (isolated SE MA) | Noticeable cooling into weekend |
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Additional Resources
- NBC Boston
- Boston 25 News
- Boston Herald
- CBS News
- Wikipedia: Weather in Boston
- Google Search: Boston weather
- Boston Globe
- NBC Boston Live Radar
- Encyclopedia Britannica: Boston
- Google News: Boston weather forecast
Author: STAFF HERE BOSTON WRITER
BOSTON STAFF WRITER The BOSTON STAFF WRITER represents the experienced team at HEREBoston.com, your go-to source for actionable local news and information in Boston, Suffolk County, and beyond. Specializing in "news you can use," we cover essential topics like product reviews for personal and business needs, local business directories, politics, real estate trends, neighborhood insights, and state news affecting the area—with deep expertise drawn from years of dedicated reporting and strong community input, including local press releases and business updates. We deliver top reporting on high-value events such as Boston Marathon, Head of the Charles Regatta, and Boston Harborfest. Our coverage extends to key organizations like the Greater Boston Chamber of Commerce and Associated Industries of Massachusetts, plus leading businesses in finance, biotech, and insurance that power the local economy such as Fidelity Investments, Biogen, and Liberty Mutual Insurance. As part of the broader HERE network, we provide comprehensive, credible insights into Massachusetts's dynamic landscape.
