The U.S. Drought Monitor draws a map every week, and the National Drought Mitigation Center publishes the share of each county that falls in each drought category. This page adds up those weekly maps for the seven counties we work in, so you can see how often dry conditions have been part of the picture. It is background, not a forecast.
How the table works
A week counts toward the second column when any part of the county was mapped in moderate drought (D1) or worse that week. The fourth column counts the weeks when half the county or more was. Extreme drought (D3) is the most severe category the table counts. Weeks are assigned to the year of the map date, so some years have 53.
Because a county map covers a large area and a week counts when only a corner of the county is in drought, the numbers are generous toward drought. Use them to compare counties and years, not to say that every yard was dry.
What stands out
In every county, some part of the county was in drought in more than half of all weeks since 2000.
- Washoe County leads at 926 of 1,357 weeks (68%), then Mineral (66%), Churchill and Lyon (64%), Storey (62%), Douglas (58%) and Carson City (54%).
- Weeks with half the county or more in drought: Churchill 832, Washoe and Lyon 791 each, Storey 777, Mineral 773, Carson City 702 and Douglas 675.
- Weeks with any part in extreme drought: Washoe 459, Mineral and Churchill 433, Lyon 386, Storey 274, Douglas 252 and Carson City 238.
- The worst years were 2013 for Washoe, Mineral, Churchill and Lyon, and 2015 for Storey, Douglas and Carson City. In Washoe County extreme drought was on the map for all 53 weeks of 2013 and for 52 weeks in each of 2004, 2014, 2015 and 2021.
- Some years were clear: Washoe had no drought weeks in 2000 or 2006, and Carson City none in 2000, 2006, 2011 or 2019.
What it means for trees
Years of dry conditions stress trees in slow ways: smaller leaves, thin crowns, dieback at the tips and more dead wood. An arborist checks where the dieback starts. Our drought stress and dieback page covers identification, and the mature tree watering guide covers the water side. If a tree has too much dead wood, the usual answers are dead wooding or, where the tree is failing, removal after a certified arborist's assessment.
Drought also dries the fuel that wildfire needs. That connects this page to wildfire risk by community and to defensible space.
Limits of the data
A drought map measures moisture conditions across a county from rainfall, snowpack, streamflow and other inputs. It does not measure the water in your soil or the condition of any tree. Irrigated trees can be healthy in a drought year, and unwatered ones can be stressed in a wet one. The table starts in 2000, so earlier droughts are not shown.
A county average also hides elevation: the same week can be dry in the valley and wetter at Tahoe.