New Years Eve won’t arrive until Dec. 31 for us civilians. But if you’re a hydrologist, 2025 ended Sept. 30 — the 2025 water year, that is.
Those who study water on and under the ground use the period from Oct. 1 through Sept. 30, to track streams, precipitation and water tables rather than a typical calendar year. The water year more closely hews to the natural cycles of water table replenishment and depletion that begins as the hot summer wanes and agricultural water use lessens.
How did the 2025 water year stack up? Here is a look at data about precipitation, streamflow, well depths and drought conditions over the last 12 months.
Precipitation
СŷƵ tracked for the last 80 years and found that 2025 tied with 1992 for 11th driest in that period, totaling just over 37 inches of precipitation. The table below shows the 15 wettest and driest years.
The total for this year is slightly more than half of the record-high 71.5 inches that fell Oct. 1, 1951, through Sept. 30, 1952. But it’s almost 10 inches more than the 28.1 inches recorded during the 2002 water year.
This year is more than 11 inches lower than the 10-year average precipitation recorded at СŷƵ International Airport, which is 48.3 inches. The blue bars in the graph below indicate total precipitation for each water year, while the orange line shows the 10-year rolling average of water year precipitation. Hover over the graph to see individual data points.
Within the 2025 water year lay extremes obscured by the annual total, including the driest October on record — only 0.02 inches of precipitation for the month — and the second-wettest May, with 10.45 inches of rain, falling on 22 out of 31 days, with another two days showing a trace.
The following chart breaks out the monthly precipitation totals and compares them with the average for the last 30 years. Only March, with 3.7 inches, and May topped the average.
Is the СŷƵ in a drought?
The year began with a record-dry October and a drought declaration that lasted 35 weeks, until the first week of June, following May’s near-record rainfall. But recent dry conditions are threatening another drought designation.
So far, the region has been able to avoid a formal drought watch from the Pennsylvania Department of Environmental Protection. On Oct. 6, the DEP issued such a declaration for 25 counties, mostly in western and north central Pennsylvania. The nearest county to the СŷƵ included under the watch is Schuylkill County.
As of Sept. 30, a moderate drought condition was designated for a tiny sliver of Northampton County’s border with Monroe, amounting to less than 1% of the county’s 370 square miles.
The vast majority of the two counties are experiencing dry conditions, according to the . The agency considers four conditions to determine drought status — groundwater levels, precipitation, surface water and the Palmer Drought Index, which indicates relative dryness.
According to the USGS’ latest monitoring report, Lehigh County is in a drought watch status for groundwater levels and precipitation, while Northampton County is in a drought warning status for precipitation, but normal for surface water, groundwater and the Palmer Drought Index.
These two graphs show how far beneath the surface one has to drill to hit water in the local observations wells in Upper Macungie Township and Jacobsburg state park.
Lehigh County’s observation well, in the Haafsville section of Upper Macungie, showed significant recovery since hitting its low water point of 74.3 feet below ground Feb. 13. It topped out at 57.9 June 20. But it’s been mostly downhill since then, with the water table dropping almost 14 feet to end the water year at 71.7 feet below ground.
Northampton’s well at Jacobsburg state park shows a similar slide, with water sequestered 47.6 feet below the surface, a tenth of an inch shy of the greatest depth seen Dec. 11. The water table had been as high as 30.6 feet May 20, more than 17 feet higher than current levels.
Waterways
The flows of area creeks and rivers are affected by both water falling from the sky and aquifers below ground. Smaller streams, like the Jordan Creek, with few tributaries and smaller drainage areas (76 square miles at the Whitehall monitoring station), are much quicker to respond to runoff from storms than large rivers like the Delaware, with many tributaries and a drainage area of 6,328 square miles at the Riegelsville monitoring station.
The graphs below show both the maximum discharge rates and stream depths for the Jordan Creek in Whitehall, the Lehigh River in Bethlehem and the Delaware River at Riegelsville for each day of the 2025 water year. Discharge is measured in cubic feet per second. A cubic foot contains slightly under 7.5 gallons of water.
The depth graphs indicate the levels at which streams may have hit one of the four flood levels designated by the USGS: action stage, minor flood, moderate flood or major flood. The year’s relatively dry conditions did not push any area waterways past minor flood stage.
The discharge rate of the creek varied widely throughout the water year, from a low of 6 cubic feet per second on Oct. 30, to a high of 1,820 cubic feet per second Dec. 23, more than 300 times the lowest flow rate. The December deluge pushed the creek to action stage, but it was still more than 9 inches below the minor flood stage of 8 feet.
The Lehigh River drains water from 1,279 square miles at the monitoring station near the Fahy Bridge in Bethlehem, so its variations in flow and depth are of a smaller amplitude than those of the Jordan Creek. Still, the river saw its flow rate vary from 432 cubic feet per second Nov. 13 to 14,200 cubic feet per second May 9, a 33-fold increase. The May zenith came as 1.52 inches of rain fell quickly after about 3 inches fell on the watershed in the preceding days.
The Lehigh’s wide riverbed helped absorb changes in depth. The Nov. 13 nadir in flow translated to a depth of 1.08 feet, while the May 9 peak flow pushed the river to a depth of 7.2 feet, almost 5 feet under action stage for that location.
The Delaware River, as tracked at Riegelsville in Bucks County, drains an area larger than the states of Connecticut and Rhode Island combined, so it is less affected by the kind of localized storms the СŷƵ experienced this water year, such as mid July, where one area got barely a trace of rain while another got half a foot. While the Delaware’s flow changed by a factor of 24, increasing from 2,960 cubic feet per second Oct. 1 to 71,800 cubic feet per second May 10, its depth changed by only a factor of 6, from 2.7 feet to 16.6 feet on the same dates.
The May storms put the river in action stage, but it remained more than 5 feet below minor flood stage.
What’s ahead?
The National Weather Service’s Climate Prediction Center is not updating its outlook due to the government shutdown. The last update, Sept. 27, predicts that the СŷƵ will remain dry over the next three months, as seen in the map image below.
Areas of Schuylkill County are expected to see very dry conditions, while much of the central and southwestern parts of the state should see wetter than average conditions. The NWS lists its confidence level in the long-term outlook as moderate.
