Drought in Chester County, PA: 1.2 years in 10 since 2000

1.2 years in 10

Chester County, PA: 3 of 26 full years had 13+ weeks in drought. Less drought-prone than most US counties.

1. 0
2. 11
3. 46
4. 0
5. 0
6. 2
7. 1
8. 3
9. 0
10. 0
11. 0
12. 2
13. 6
14. 0
15. 0
16. 0
17. 6
18. 10
19. 0
20. 5
21. 0
22. 0
23. 5
24. 8
25. 14
26. 32

20002025

Drought years: 2002 (46 wk), 2024 (14 wk) and 2025 (32 wk). Not a single drought week in 2000, 2003, 2004, 2008, 2009, 2010, 2013, 2014, 2015, 2018, 2020 and 2021.

A regular lawn is fine here; plan for the odd dry year

Real droughts are rare here. A smart controller that skips watering after rain covers the odd dry year.

You can keep a regular lawn. Worth doing: a rain-sensing or smart controller, and deeper, less frequent watering if Apr turns dry.

Against the rest of PA

5th most drought-prone of 67 PA counties; the PA middle is 0.8 in 10. Closest on the list: Lebanon County (1.5 in 10) and York County (1.2 in 10). Driest in PA: Adams County (1.9 in 10). Least drought: Susquehanna County (0 in 10).

When in the year it hits

Most often in Apr (18% of weeks), then Oct (18%) and Dec (17%). Least in Sep (5%). May to September averages 9%.

1. 15 Jan
2. 15 Feb
3. 15 Mar
4. 18 Apr
5. 14 May
6. 10 Jun
7. 8 Jul
8. 8 Aug
9. 5 Sep
10. 18 Oct
11. 16 Nov
12. 17 Dec

The worst year: 2002

2002: 46 weeks in drought, peaking at D4 exceptional. Across 1,401 weekly maps: 13.1% of all weeks at D1 or worse, 5.2% at D2, 1.3% at D3, 1 weeks with some of the county in D4. Longest unbroken spell: 55 weeks, Oct 30, 2001 to Nov 12, 2002.

Lately

Last drought year: 2025, 32 weeks. 2016-2025: 2 in 10, against 0.6 in 10 for 2000-2015, about the same. So far in 2026: 33 of 44 weeks in drought, through Nov 3, 2026.

Further reading

Chester County lands on the plan covered in keeping a regular lawn. Its worst year, 2002, was not one of the big national drought years; see the worst years since 2000. How each of Chester County's 1,401 weeks was judged: how drought is counted.