Every measurement on this Big Bear Lake weather page comes from a live public data source. This breaks down what each one means and how current it is.
Right now
These update every time the page loads and reflect conditions at this exact moment.
- Temperature & Feels Like
- Actual air temperature and perceived temperature accounting for wind and humidity. Source: Open-Meteo.
- Wind & Wind Gusts
- Sustained wind speed/direction and peak gust speed, measured now. Source: Open-Meteo.
- Humidity
- Current relative humidity. Source: Open-Meteo.
- Air Quality
- Current U.S. EPA Air Quality Index. Source: Open-Meteo Air Quality API.
- Pressure
- Current barometric pressure at sea level, with a trend arrow from the past several hours. Source: Open-Meteo.
- Cloud Cover
- Percentage of sky currently covered by cloud, measured right now. The forecast below can still show a later chance of rain even on a currently clear reading. Source: Open-Meteo.
Today & the 16-day outlook
These are forecasts for the full day ahead. A clear sky right now can still be followed by rain later that same day.
- UV Index
- Today's forecasted maximum while the sun is up. Shows zero after sunset, since UV exposure is genuinely zero at night regardless of how high the day's peak was. The sunset time shown is astronomical sunset — in a mountain valley like Big Bear, the sun can disappear behind the surrounding ridgelines noticeably earlier than that. Source: Open-Meteo.
- Rain Today / Snow Today
- Today's total accumulation so far. Source: Open-Meteo.
- Day Icon & Description
- A short summary of that day's expected conditions (e.g. "Overcast," "Light Rain"), based on Open-Meteo's forecasted weather code for the day. Source: Open-Meteo.
- Chance of Precip
- That day's maximum probability of precipitation. Source: National Weather Service where available, otherwise Open-Meteo.
- Precip Amount
- Expected rain or snow accumulation for the day, shown only when the forecast calls for a meaningful amount. Source: Open-Meteo.
- High / Low
- That day's forecasted high and low temperature. Source: Open-Meteo.
Radar & alerts
- Radar map
- Live NEXRAD reflectivity imagery centered on Big Bear Lake, typically a few minutes behind real time, animated across the past two hours. Source: RainViewer.
- Radar legend
- Blue through green is light precipitation; yellow and orange is moderate; red and purple is heavy. The scrubber can be dragged or stepped with the arrow keys to any frame in the loop.
- Base map
- The street and terrain map underneath the radar. Source: Esri.
- Active alerts
- Official watches, warnings, and advisories currently in effect for Big Bear Lake and the surrounding San Bernardino Mountains. Source: National Weather Service.