Zone 1 Aug. 1 - Aug. 10 | Zone 2 Aug. 11 - Aug. 20 | Zone 3 Aug. 21 - Aug. 31 | Zone 4 Sep. 1 - Sep. 10 | Zone 5 Sep. 11 - Sep. 20 | Zone 6 Sep. 21 - Sep. 30 |
Zone 7 Oct.1 - Oct. 10 | Zone 8 Oct.11 - Oct. 20 | Zone 9 Oct. 21 - Oct. 31 | Zone 10 Nov. 1 - Nov. 10 | Zone 11 Nov. 11 - Nov. 20 | Zone 12 Nov. 21 - Nov. 30 |
Zone 13 Dec. 1 - Dec. 10 | Zone 14 Dec. 11 - Dec. 20 | Zone 15 Dec. 21 - Dec. 31 | Zone 16 Jan. 1 - Jan. 10 | Zone 17 Jan. 11 - Jan. 20 | Zone 18 Frost Rare |
Plantmaps has derived zones indicating the average annual First frost dates for Latvia