Weather
Tonight’s observing conditions in Naperville, and the next two nights.
Clouds, sky clarity and steady air for every hour of the next 3 days.
The Environment Canada forecast maps, centered on Naperville.
This is a prediction from a weather model, not a report of the sky right now. It’s not always correct, so check the sky before you head out.
Tonight in Naperville
Good
Bright MoonClear skies all night, from dark at 7:35 PM until 5:40 AM.
- Cloud Cover
- Clear
- Sky Clarity
- Good
- Steady Air
- Average
What These Mean
Excellent, Good, Average, PoorHow good the sky is for observing while it’s clear. “Clouded Out” means there’s no break in the clouds of two hours or more; “No Data” means the forecast didn’t cover it.
Cloud CoverHow much of the sky is covered while it’s dark. More bars is a clearer sky.
Sky ClarityHaze in the air (transparency). Matters most for the Milky Way and galaxies.
Steady AirHow much stars twinkle (seeing). Matters most for the Moon and planets.
Bright MoonThe Moon is more than half lit and up for most of the night. It washes out faint galaxies and the Milky Way.
More gold bars is better.
Tonight’s Sky Waxing Gibbous Moon · Up at 8 PM: Saturn, Neptune What to See Tonight →
Next 3 Nights
Dark to dawn. Dark blue is clear sky, light blue is partly cloudy, gray is clouds. The rating is how good the sky is while it’s clear.
Tonight
Good
Bright MoonClear skies all night, from dark at 7:35 PM until 5:40 AM.
While clear: Sky Clarity Good · Steady Air Average
Friday Night
Average
Bright MoonClear skies all night, from dark at 7:35 PM until 5:40 AM.
While clear: Sky Clarity Average · Steady Air Average
Saturday Night
Average
Bright MoonMostly clear all night, with some passing clouds.
While clear: Sky Clarity Poor · Steady Air Good
Every Hour
Clouds, sky clarity, steady air and darkness (with the Moon) for the next 3 days, day and night. Darker blue is better.
Bookmark naperastro.org/weather/#charts to open here.
Environment Canada Forecast Maps
Naperville is circled in red. Model run Oct 22, 7:00 AM CDT. More maps at weather.gc.ca.
Weather data provided by Environment and Climate Change Canada (astronomy forecasts), used under the Data Server End-use Licence. Model run Oct 22, 7:00 AM CDT, updated every 6 hours.
Forecast concept from Attilla Danko’s Clear Sky Charts at cleardarksky.com.
The Sun
Thursday: Sunrise 7:10 AM · Sunset 6:00 PM
Northern Lights
Unlikely
Activity is Kp 5 as of 4 PM. Naperville usually needs Kp 7 or higher.
Source: NOAA planetary K-index
Sunspots
3 Spot Groups
31 sunspots in all. The largest group, region 4551, covers about the area of 8 Earths. Region 4560 is the most likely to flare.
Source: NOAA solar region summary
Solar Flares
Moderate
NOAA’s forecast chance of a flare in the next 24 hours.
Source: NOAA solar activity forecast
Solar Cycle 25 is past its peak and winding down. September's sunspot number was 69. Solar cycle progression from NOAA’s Space Weather Prediction Center.
Never look at the Sun, even briefly, without a proper solar filter.