Counties in Maryland by annual precipitation

St. Mary's County had the highest annual precipitation of 24 counties in 2015, at 50.18 inches. Washington County had the lowest, at 35 inches. The median was 48.05 inches and the figure for Maryland was 46.86 inches. Source: NOAA National Centers for Environmental Information.

Highest50.18St. Mary's County

Lowest35Washington County

Median48.0524 counties

Maryland46.86History

Map of counties, 2015

Under 46
46 to 47
47 to 49
49 to 50
50 and over

inches, 2015. Source: NOAA NCEI, NOAA Climate at a Glance, January to December precipitation, counties. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2015

inches. Source: NOAA NCEI, NOAA Climate at a Glance, January to December precipitation, counties. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2015 inches	Change on 2014
1	St. Mary's County	50.18	+28.3%
1	Worcester County	50.18	+21.5%
3	Calvert County	50.04	+21.8%
4	Harford County	49.69	+1.4%
5	Howard County	49.68	-3.9%
6	Wicomico County	49.56	+13.2%
7	Baltimore city	49.2	-12.4%
8	Somerset County	49.17	+17.8%
9	Kent County	49.09	+6.2%
10	Baltimore County	48.7	-7.9%
11	Cecil County	48.64	-2.8%
12	Anne Arundel County	48.36	-0.9%
13	Dorchester County	47.74	+14.3%
14	Talbot County	47.66	+13.1%
15	Garrett County	47.3	+6.6%
16	Queen Anne's County	47.09	+8.6%
17	Prince George's County	46.68	0%
18	Charles County	46.58	+15.4%
19	Carroll County	46.18	-3.2%
20	Caroline County	46.02	+7.4%
21	Montgomery County	45.24	-4.6%
22	Frederick County	43.64	-6.6%
23	Allegany County	39.53	+8.4%
24	Washington County	35	-15%

Other periods

About this ranking

Total precipitation from January to December, in inches: rain plus the water content of snow and other frozen precipitation. NOAA computes it from its climate divisional dataset (nClimDiv): station readings interpolated onto a 5 km grid and averaged over the area.

Values are area averages, not the reading at one weather station. NOAA revises the last two years every month.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December precipitation, counties. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

NOAA National Centers for Environmental Information. (2026). NOAA Climate at a Glance, January to December precipitation, counties (Counties in Maryland by annual precipitation, 2015) [Data set]. Retrieved October 12, 2026, from https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping

MLA 9

NOAA Climate at a Glance, January to December precipitation, counties, Counties in Maryland by annual precipitation, 2015. NOAA National Centers for Environmental Information, 6 Oct. 2026, https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Invokely, https://invokely.ai/rankings/annual-precipitation/maryland-counties?period=2015. Accessed 12 Oct. 2026.

Chicago (author-date)

NOAA National Centers for Environmental Information. 2026. NOAA Climate at a Glance, January to December precipitation, counties. Counties in Maryland by annual precipitation, 2015. Dataset. Accessed October 12, 2026. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Also distributed by Invokely, https://invokely.ai/rankings/annual-precipitation/maryland-counties?period=2015.

Harvard

NOAA National Centers for Environmental Information (2026) NOAA Climate at a Glance, January to December precipitation, counties, Counties in Maryland by annual precipitation, 2015 [Dataset]. Available at: https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping, via Invokely: https://invokely.ai/rankings/annual-precipitation/maryland-counties?period=2015 (Accessed: 12 October 2026).

BibTeX

@misc{noaa_counties_in_maryland_by_2015,
  author = {{NOAA National Centers for Environmental Information}},
  title = {{NOAA Climate at a Glance, January to December precipitation, counties: Counties in Maryland by annual precipitation, 2015}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/annual-precipitation/maryland-counties?period=2015. Publisher attribution: NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December precipitation, counties. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Retrieved 2026-10-12.},
}

RIS

TY  - DATA
AU  - NOAA National Centers for Environmental Information
TI  - NOAA Climate at a Glance, January to December precipitation, counties: Counties in Maryland by annual precipitation, 2015
PY  - 2026
DA  - 2026/10/06
PB  - NOAA National Centers for Environmental Information
DB  - Invokely
UR  - https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping
L2  - https://invokely.ai/rankings/annual-precipitation/maryland-counties?period=2015
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/annual-precipitation/maryland-counties?period=2015.
N1  - Publisher attribution: NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December precipitation, counties. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Retrieved 2026-10-12.
ER  -

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Questions

Which county has the highest annual precipitation?

St. Mary's County, with 50.18 inches in 2015, according to NOAA National Centers for Environmental Information.

Which county has the lowest annual precipitation?

Washington County, with 35 inches in 2015.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: NOAA National Centers for Environmental Information, NOAA Climate at a Glance, January to December precipitation, counties. Retrieved 2026-10-12.