Weather forecast accuracy details for Portland, Maine

These are the one- to three-day out accuracy percentages for high temperature, low temperature, icon forecast precipitation (both rain and snow), and text forecast precipitation (both rain and snow). Temperature accuracy is the percentage of forecasts within three degrees. Precipitation accuracy is the percentage of correct forecasts. The forecasts are collected in the evening.

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Weather Forecast Accuracy Data Last Month (October)

Provider High Temp Low Temp Icon Precip Text Precip Overall
The Weather Channel   86.02% 63.44% 92.47% 92.47% 83.60%
Foreca/Vaisala   86.02% 68.82% 89.25% 89.25% 83.33%
Weather Underground   84.95% 61.29% 88.17% 88.17% 80.65%
AerisWeather   74.19% 52.69% 90.32% 90.32% 76.88%
AccuWeather   70.65% 61.29% 88.04% 85.87% 76.46%
Wetter   84.95% 45.16% 86.02% 83.87% 75.00%
Weather News   73.12% 49.46% 86.02% 86.02% 73.66%
OpenWeather   80.65% 33.33% 89.25% 89.25% 73.12%
NWS Digital Forecast   51.61% 60.22% 89.25% 89.25% 72.58%
Weatherbit   78.26% 33.70% 88.04% 88.04% 72.01%
World Weather Online   68.89% 30.00% 90.00% 90.00% 69.72%
Dark Sky   18.28% 30.11% 90.32% 90.32% 57.26%
Persistence   44.93% 23.19% 56.52% 56.52% 45.29%

Weather Forecast Accuracy Data Last Year (2021)

Provider High Temp Low Temp Icon Precip Text Precip Overall
The Weather Channel   79.78% 79.96% 86.61% 86.61% 83.24%
Weather Underground   80.06% 80.06% 82.83% 82.83% 81.44%
Foreca/Vaisala   77.22% 75.65% 86.45% 86.02% 81.34%
AccuWeather   78.24% 76.73% 83.62% 80.39% 79.75%
AerisWeather   72.96% 67.31% 83.43% 83.43% 76.78%
NWS Digital Forecast   65.08% 70.86% 75.86% 75.86% 71.92%
World Weather Online   61.94% 58.61% 76.48% 76.48% 68.38%
Wetter   69.25% 49.49% 76.82% 76.45% 68.01%
Weatherbit   64.92% 50.56% 78.04% 78.04% 67.89%
OpenWeather   64.82% 49.68% 77.93% 77.93% 67.59%
Dark Sky   50.32% 44.32% 86.24% 86.24% 66.78%
Weather News   63.27% 57.80% 63.37% 63.37% 61.95%
Persistence   30.83% 29.13% 51.38% 51.38% 40.68%

If this data feeds your inner weather geek, you'll probably be interested in the amazing amount of weather data available from ForecastWatch. Likewise, if you're looking to assess your own forecasting accuracy or would like to make more informed decisions about a weather provider you're considering or already use, we can provide data to help you.

The data here is calculated from forecasts and observations collected and analyzed by ForecastWatch. If you would like more information about the methods, scientific approach, and the quality controls employed to ensure the data and analyses are of the highest quality, please read this overview.

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