MEDIAN FLOW RATE · 30 DAY
7cfs 35.9% vs avg
Optimal band: 6–8 cfs
PERIOD HIGH
11cfs
PERIOD LOW
5cfs
RUNNABLE
71%
last 30 day in band
Gauge Height
1.09ft
Precipitation History
Precipitation · YTD
NormalNear-normal year
2026 to date
21.2in
≈ normal
21.19 in of precipitation so far this year — about average for this point in the season (normal 21.18 in).
YTD Total
21.2in
This year so far
Normal to Date
21.2in
30-yr average
Typical Range
16.5–26.7in
10th–90th pct YTD
Departure
0%
vs 30-yr normal
By Month
This year
Typical range
Normal
Jan: 2.38" · normal 3.03" (1.6–4.9)
Feb: 2.18" · normal 2.66" (1.3–4.9)
Mar: 3.55" · normal 3.77" (1.7–5.2)
Apr: 1.94" · normal 3.45" (2.0–5.3)
May: 5.08" · normal 3.69" (1.4–5.6)
Jun: 3.08" · normal 3.36" (1.7–5.5)
Jul: 2.99" (so far)· normal 3.36" (1.8–5.3)
Aug: normal 2.77" (1.5–4.2)
Sep: normal 4.12" (1.2–7.8)
Oct: normal 3.27" (0.8–5.5)
Nov: normal 2.92" (1.3–4.4)
Dec: normal 3.34" (1.7–4.9)
Baseline 1991–2020 · Source: Open-Meteo06:38 UTC
Your History · MARSH RUN AT GRIMES, MD
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Station Location
39.5146, -77.7772Loading map…
DATA · USGS · NOAA · NWSUPDATED 2026-07-12 00:00 UTC
Site #01617800·USGS
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