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Gray Line Map

A live map of the day/night terminator and the subsolar point. Stations near the dashed line are in the gray zone, the best time for long-distance DX on 160 to 30 metres.

Day and night around the world

--:-- UTC Subsolar point: -- Solar declination: --

The shaded area is night. The orange band marks the gray line (terminator), where the D layer is weak and the F layer still reflects. The map is computed in your browser from the current time and updates every minute. Map data © OpenStreetMap contributors.

Using the gray line

Find your own sunrise and sunset with the grid locator sun calculator.
Work stations that are in twilight at the same time as you, mainly on 160, 80, 40 and 30 metres.
Windows are short, often 30 to 60 minutes, and move a few minutes every day.
Combine with the current band conditions to choose the right band.

Why it works

Along the terminator the D layer is fading or not yet formed, so absorption is low, while the F layer still reflects. Signals can run along the twilight zone for thousands of kilometres. Read the full gray line guide.

Data: NOAA Space Weather Prediction Center, NASA SDO. Band conditions are estimates computed by Map For HAM and are indicative only. Methodology and credits · Data feeds · Widgets