27-day aurora forecast

The Sun turns once every 27 days as seen from Earth, so active regions and coronal holes often come back. NOAA uses that to publish a long-term outlook of the largest Kp for each day.

In short: 4 of the next 27 days show a largest Kp of 5 or more (storm level): Oct 19, Oct 20, Oct 31, Nov 1. Sudden storms are not in this outlook.

Day (UTC)	Largest Kp	Fairbanks, AK	International Falls, MN	Marquette, MI	Plattsburgh, NY	Fort Collins, CO
Mon, Oct 19	5 (G1)	Good chance	Good chance	Good chance	Possible	Unlikely
Tue, Oct 20	5 (G1)	Good chance	Good chance	Good chance	Possible	Unlikely
Wed, Oct 21	4	Good chance	Possible	Low chance	Low chance	Unlikely
Thu, Oct 22	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Fri, Oct 23	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Sat, Oct 24	4	Good chance	Possible	Low chance	Low chance	Unlikely
Sun, Oct 25	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Mon, Oct 26	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Tue, Oct 27	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Wed, Oct 28	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Thu, Oct 29	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Fri, Oct 30	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Sat, Oct 31	5 (G1)	Good chance	Good chance	Good chance	Possible	Unlikely
Sun, Nov 1	5 (G1)	Good chance	Good chance	Good chance	Possible	Unlikely
Mon, Nov 2	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Tue, Nov 3	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Wed, Nov 4	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Thu, Nov 5	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Fri, Nov 6	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Sat, Nov 7	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Sun, Nov 8	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Mon, Nov 9	4	Good chance	Possible	Low chance	Low chance	Unlikely
Tue, Nov 10	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Wed, Nov 11	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Thu, Nov 12	3	Good chance	Low chance	Unlikely	Unlikely	Unlikely
Fri, Nov 13	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely
Sat, Nov 14	2	Good chance	Unlikely	Unlikely	Unlikely	Unlikely

Outlook issued 2026 Oct 19 0141 UTC. Each place column compares the day's largest Kp with the Kp that place needs (our estimate). Clouds and the Moon are not included this far ahead.

How reliable is it?

The 27-day outlook catches recurring activity well, such as coronal holes that send fast solar wind every rotation. It cannot know about new sunspot regions or eruptions that have not happened yet. Use it to plan which week to watch, then check the 3-day forecast and the Kp index on the night.

Source: NOAA Space Weather Prediction Center, 27-day space weather outlook table (public domain). Unofficial copy for general information.

Page built: October 25, 2026.