Today | Weather | Wednesday, October 1, 2025
Active Weather Warnings

Weather in Waltham, Massachusetts

02:29 PM
Now
Sunny Weather
64° F
Feels Like 61°
Precipitation 0 %
Wind 23 mph
UV Index (0 - 11+) 11
Humidity 44 %
Today
Sunny Weather
Day 64°
Night 41°
Precipitation 0 %
Wind 16 mph
UV Index (0 - 11+) 11

Warning: Extreme UV Index Today: 11+

Overexposure to the sun's harmful UV rays can cause sunburn and increase the risk of developing skin cancer, including melanoma. Protect yourself by wearing clothing that covers your skin, sunglasses, and a hat. Apply a broad-spectrum sunscreen with an SPF of 30 or higher every two hours, even on cloudy days. Minimize direct sun exposure during peak hours (10 AM to 4 PM) to reduce the risk.

Waltham Weather Forecast Updated

11 minutes ago
Last updated on

Air quality in Waltham

NOW
31 AQI
Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 1.41 µg/m³
PM10 1.72 µg/m³
O₃ 34.26 ppb
NO₂ 1.26 ppb
SO₂ 0.31 ppb
CO 131.59 ppb
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide

Health Recommendations:

With this level of air quality, you have no limitations. Enjoy the outdoors

Weather Alerts and Warnings for Waltham

Moderate Expected Observed

Special Weather Statement

Special Weather Statement issued September 30 at 1:41PM EDT by NWS Boston/Norton MA
Sep 30, 1:41 PM Oct 1, 7:00 PM
There is an elevated fire risk on Wednesday, due to combinations of
factors; north-northeast gust up to 20 MPH, relative humidity values
between 35 and 40 percent, and drought-stressed fuel littering the
ground. A period between late-morning and sunset are expected to
bring the lowest RH values and strongest wind gusts.

This forecast takes into account meteorological, fuel, and land
conditions, and was developed in coordination with state fire and
land management officials.

Open burning is not recommended on Wednesday. Follow instructions of
local fire wardens. Be very careful when handling and disposing of
ignition sources outdoors, such as cigarettes or matches.
Updated: Oct 1, 2:18 PM Source: NWS Alert