DroughtOdds

Drought in Lewis and Clark County, MT: 6.2 years in 10 since 2000

6.2 years in 10

Lewis and Clark County, MT: 16 of 26 full years had 13+ weeks in drought. More drought-prone than most US counties.

  1. 22
  2. 46
  3. 53
  4. 52
  5. 52
  6. 47
  7. 27
  8. 24
  9. 21
  10. 4
  11. 15
  12. 0
  13. 10
  14. 0
  15. 0
  16. 27
  17. 19
  18. 12
  19. 0
  20. 0
  21. 7
  22. 23
  23. 52
  24. 10
  25. 51
  26. 52

20002025

Drought years: 2000 (22 wk), 2001 (46 wk), 2002 (53 wk), 2003 (52 wk), 2004 (52 wk), 2005 (47 wk), 2006 (27 wk), 2007 (24 wk), 2008 (21 wk), 2010 (15 wk), 2015 (27 wk), 2016 (19 wk), 2021 (23 wk), 2022 (52 wk), 2024 (51 wk) and 2025 (52 wk). Not a single drought week in 2011, 2013, 2014, 2018 and 2019.

Plan for drought as normal: shrink the lawn, go drip and natives

Drought is the normal state of things here. Most of the yard goes to natives and gravel on drip; any grass that stays is a small, tough patch.

If you are replacing turf, plant natives in fall so roots set before the Oct peak, and check your water utility for a turf-removal rebate before you dig.

Against the rest of MT

9th most drought-prone of 56 MT counties; the MT middle is 5.4 in 10. Closest on the list: Silver Bow County (6.2 in 10) and Carbon County (6.2 in 10). Driest in MT: Glacier County (6.9 in 10). Least drought: Garfield County (3.8 in 10).

When in the year it hits

Most often in Oct (62% of weeks), then Sep (59%) and Aug (53%). Least in Jun (30%). May to September averages 44%.

  1. 43 Jan
  2. 49 Feb
  3. 43 Mar
  4. 42 Apr
  5. 38 May
  6. 30 Jun
  7. 42 Jul
  8. 53 Aug
  9. 59 Sep
  10. 62 Oct
  11. 50 Nov
  12. 44 Dec

The worst year: 2003

2003: 52 weeks in drought, peaking at D4 exceptional. Across 1,401 weekly maps: 46.2% of all weeks at D1 or worse, 26.7% at D2, 7.2% at D3, 86 weeks with some of the county in D4. Longest unbroken spell: 227 weeks, Feb 13, 2001 to Jun 14, 2005.

Lately

Last drought year: 2025, 52 weeks. 2016-2025: 5 in 10, against 6.9 in 10 for 2000-2015, about the same. So far in 2026: 21 of 44 weeks in drought, through Nov 3, 2026.

Further reading

Lewis and Clark County lands on the plan covered in shrinking the lawn. Its worst year, 2003, was not one of the big national drought years; see the worst years since 2000. How each of Lewis and Clark County's 1,401 weeks was judged: how drought is counted.