Topsham, ME Weather Forecast
Sagadahoc County, Maine
Seven-day outlook
30–63°F across the weekThe week runs between 30° and 63°, with tomorrow the warmest day of it. There is no real trend across it: one day looks much like the next. Every day in the outlook stays dry.
Forecasts come from the National Weather Service's own computer models, and current conditions from the nearest reporting weather station. Both are served through the weather API. A forecast is guidance, not a warning, and anything the Weather Service has actually issued is on the live map.
The written summaries on this page are generated from the forecast data above, not by a meteorologist. Each sentence is a reading of the same numbers you can see, and no forecaster has reviewed them.
About the Topsham forecast
Topsham sits at 43.9650°N, 69.9556°W in Sagadahoc County, Maine. The forecast above is drawn for that point from the National Weather Service's own computer models: a seven-day outlook, and a finer-grained one covering the next eighteen hours where it reaches, and the radar and alert panels show what the Weather Service has out over the area right now.
- County
- Sagadahoc County
- Coordinates
- 43.9650°N, 69.9556°W
- Population
- 9,751 · 2023 estimate
- Land area
- 32.178 sq mi
Place data from the US Census Bureau. Coordinates are the Census internal point for Topsham, and the forecast is for that location, not for every address inside the city limits, and a large city can have real weather differences from one side to the other.
How well can the network see Topsham?
The nearest Doppler radar is KGYX (Portland, ME), 16 miles to the WSW. A WSR-88D's lowest routine scan sits half a degree above horizontal, and the earth curves away beneath it, so by the time that beam reaches Topsham its center is about 850 ft above ground. That is about as close as radar coverage gets in the United States: the lowest scan is still near the ground when it reaches Topsham, so low-level rotation and the leading edge of a gust front show up on it. Topsham is closer to its radar than 90% of US cities.
The closest instrument actually measuring the air is KBXM · Brunswick Exec on the ASOS/AWOS network, 5.6 miles away. Near enough to be representative on most days, though a summer thunderstorm can soak one and miss the other entirely.
Beam height is the standard 4/3-earth approximation for the 0.5° scan and assumes normal refraction; it is where the center of the beam is, not its edges, and unusual temperature profiles bend it. Radar siting from the NWS WSR-88D network, station positions from the Maine observing network as of this build.
Forecasts near Topsham
- Brunswick, ME5 mi
- Bath, ME6 mi
- Bowdoinham, ME7 mi
- Lisbon, ME7 mi
- Bowdoin, ME8 mi
- Durham, ME9 mi
- Woolwich, ME9 mi
- Sabattus, ME11 mi
Elsewhere in Maine
PortlandLewistonBangorSouth PortlandAuburnScarboroughAll Maine forecasts →