How can we show weather a year ahead?

Weather forecasts work best in the near future. Nobody can know the exact weather on a specific day eight months from now — and we’ll never pretend to.

For farther dates, LongCast looks at what the weather has actually been like around that date in past years, plus recent patterns, to tell you what’s most likely. The farther out you look, the more we show ranges and “typical” conditions instead of precise numbers.

1. Today – 2 weeks

   Forecast

   Real weather forecasts from global forecast models, with specific temperatures, rain chances, wind and UV.

2. 2 – 6 weeks

   Extended Outlook

   Typical ranges for the date, nudged by recent weather patterns. You'll see ranges, not exact numbers.

3. 6 weeks – 3 months

   Long-Range Outlook

   Mostly based on what the weather has been like on these dates over the past 10 years.

4. 3 – 12 months

   Seasonal Outlook

   What’s typical for that time of year: usual highs and lows, how often it rains, and how it usually feels.

Confidence labels

Every outlook shows a simple confidence label — High, Good, Fair or Low — so you know how much to rely on it.

Where the data comes from

Forecasts and historical weather from Open-Meteo (built on national weather services and the ERA5 climate record), and severe weather alerts from the U.S. National Weather Service.