Snowpack

Historical data on the water content of snowpack in New England are limited. For much of the late winter and spring 2022, snow water content in coastal Maine was in the lowest 10 to 25 percent of the past 10 years. By April, most of the State except northern Maine had snow water content in the lowest 10 percent of the past 10 years (Maine Geological Survey, 2022). New Hampshire had above average snow water content from the end of January through mid-February in most basins, and then average to below average snow water content in March except in the Mascoma and Lake Francis areas where it remained above average (25 to 70 years of record; New Hampshire Department of Environmental Services, 2022).

Temperature and Potential Evapotranspiration

New England was characterized by above average temperatures and above average potential evapotranspiration for much of summer 2022 (June to August), which was ranked the second warmest in Massachusetts and Rhode Island, the third warmest in Connecticut, and the fourth warmest in New Hampshire based on 128 years (1895–2022) of records (National Oceanic and Atmospheric Administration, 2022c). The meteorological station in Portland, Maine, recorded the second warmest summer on record, with an average temperature of 69.1 degrees Fahrenheit (°F), ranking only lower than summer 2020, which was the warmest on record (National Oceanic and Atmospheric Administration, 2022a). Connecticut, Rhode Island, Massachusetts, and New Hampshire recorded the warmest August on record in 128 years. The average August temperature in Massachusetts was 4.4 °F above average, the furthest from average in all New England States (National Oceanic and Atmospheric Administration, 2022c).

In Boston, Massachusetts, cumulative potential evapotranspiration (PET) stayed above average from March through August 2022, with the most rapid increase between June and mid-August. By mid-August, PET in Boston reached more than 5 inches, more than 1.5 inches above average. Cumulative PET in Caribou in northern Maine was up to 0.3 inch above average between May and mid-June and from mid-July to the end of August (National Oceanic and Atmospheric Administration, 2022b; Northeast Regional Climate Center, 2022).

Rainfall

During July to September 2021, many southern New England States had received excess rainfall due to the remnants of tropical storms Henri, Elsa, and Ida, but by November 2021, precipitation had fallen below average in many areas. In water year 2022, much of New England recorded below average precipitation, ranging from 44 inches (greater than [>] 3 inches below average) in Portland, Maine, to 30.77 inches (>16 inches below average) in Westerly, R.I., based on averages from the 1981–2010 period of record (fig. 2; National Oceanic and Atmospheric Administration, 2022a). Precipitation in Westerly was nearly 10 inches below average for water year 2022 by May and continued to decline to >18 inches below the water year average in early September (fig. 2). Stations in Boston recorded the driest May through August ever from 1884 to 2022, with only 5.74 inches of rainfall (average is 13.28 inches; National Oceanic and Atmospheric Administration, 2022a). Many areas of New England received monthly precipitation in June 2022 that was 2 to 3 inches below the average. July 2022 was ranked as the second driest July on record (1893–2022) in Rhode Island, with Providence only receiving 0.46 inch of rainfall (average 3.03 inches; National Oceanic and Atmospheric Administration, 2022a, d).

During 2022, some locations in northern New England recorded above average precipitation, including Burlington, Vermont, which received 3.6 inches more precipitation than a typical April through September period (record from 1884 to 2022). Widespread rainfall in New England in late August and early September 2022 resulted in improvements to the precipitation deficits, with most areas receiving 1 to 5 inches above average rainfall for the month of September. However, parts of Cape Cod and northeastern Massachusetts did not receive notable rainfall in September (National Oceanic and Atmospheric Administration, 2022a).

Streamflow Conditions

The New England-wide average 7-day flows at 78 streamgages fluctuated in the normal range (25th to 75th percentile) during winter 2021–22 and spring 2022, with a very brief period of below normal flows (less than 25th percentile) around the beginning of February and prolonged normal to above normal flows (>75th percentile) from the middle of February to the end of April. The average 7-day streamflows began to decline in late April and dropped below normal conditions from May 12 to 16, June 6 to 7, July 11 to 18, and August 1 to 20 (fig. 4). The lowest New England-wide average 7-day streamflow percentile for 2022 was on August 8 (18th percentile). Other notable low average 7-day streamflow percentiles were on May 14 (20th percentile) and July 14 (18th percentile). The last date of below normal average 7-day streamflows across New England was on August 20, after which streamflows continued to increase through the remainder of August and September (fig. 4).

The onset of the 2022 drought was earlier (mid-May) than the drought in 2020 (early June); however, New England-wide average 7-day streamflows did not reach the same level of dry conditions as experienced in the 2020 drought when the lowest New England-wide average 7-day streamflow was in the 6th percentile from September 23 through 28, 2020 (fig. 4; Lombard and others, 2020). Additionally, the 2020 drought had longer periods of below normal average 7-day streamflows compared with the 2022 drought. A potential reason that 2022 streamflows did not reach the lower and longer period of percentile levels as seen in 2020 (Lombard and others, 2020) is the spatial variability in the severity of the 2022 drought; sustained normal and above normal streamflows in northern Maine increased New England-wide averaged streamflow throughout the 2022 drought. September rainfalls resulted in most of New England recovering to normal to above normal streamflows (fig. 3A).

The drought in New England varied in severity over three general regions: southern New England (Connecticut, Massachusetts, and Rhode Island), central New England (southern and central Maine, New Hampshire, and Vermont), and northern Maine. Southern New England experienced widespread below normal flow conditions beginning in May, that continued into regionwide below normal flows in July and August when 9 of the 28 streamgages in Connecticut and Massachusetts recorded mean July or August 30-year record lows, with 2 of those 9 streamgages recording mean monthly lows in both July and August (fig. 3A). The 7-day average streamflow at Mill River at Northampton, Mass. (01171500) USGS streamgage reached its lowest values (4.0 ft³/s) on August 22, which is the lowest 7-day average value observed for any month during the past 30 years, including the 2020 drought (fig. 5A). In central New England, below normal conditions were most widespread in July and August when 2 of the 34 streamgages (Wild River at Gilead, Maine [01054200] USGS streamgage in July and East Orange Branch at East Orange, Vt. [01139800] USGS streamgage in August) experienced mean monthly record lows. In northern Maine, normal or above normal streamflow conditions were maintained throughout the study period. All streamgages across New England, except two streamgages in Massachusetts and one streamgage in Vermont, returned to normal or above normal streamflow conditions in September (fig. 3A). State-specific streamflow conditions are discussed briefly in appendixes 1 to 6.

Despite below normal flows observed at streamgages throughout parts of New England in 2022, only 3 of the 78 streamgages (with 30 to 120 years of record extending through September 2022) included in this study recorded the lowest 7-day average flows during the streamgage’s period of record. The Old Swamp River near South Weymouth, Mass. (01105600; period of record 1966 to 2022) USGS streamgage experienced a record 7-day average low flow on August 21; and the Mill River at Northampton, Mass. (01171500; period of record 1939 to 2022; fig. 5A) and Parker River at Byfield, Mass. (01101000; period of record 1946 to 2022) USGS streamgages experienced record 7-day average low flows on August 22. In contrast, 10 of the 78 streamgages experienced record 7-day average low flows in 2020, including two streamgages in Maine that have a period of record beginning in 1903 (USGS streamgages 01031500 and 01013500). The relative lack of streamgages that experienced record 7-day average low flows in 2022, in comparison to the 2020 drought, could be attributed to the timing of the two droughts. The drought in 2020 peaked in September, which is the month that typically experiences the lowest flows during the year (Lombard and others, 2020). The drought in 2022 peaked in August and generally returned to normal conditions in September across New England (figs. 4 and 5A).

Groundwater Conditions

Parts of northern New England, including Maine and Vermont, experienced below normal groundwater levels in the beginning of water year 2022. Most of southern New England, however, experienced normal to above normal groundwater levels at the beginning of the water year into spring 2022. Groundwater levels in 2022, especially in southern New England, had an earlier onset of widespread below normal conditions (July) than in 2020 (August; fig. 3B; apps. 1 to 6; Lombard and others, 2020). In August, groundwater levels were most severely affected by drought conditions, with more than 75 percent of the monitoring wells (95 of 126) in New England indicating below normal conditions; 16 of these represented a 25-year low for August (fig. 3B). Unlike in 2020 when water levels continued to decline further below normal past the 2020 water year, water levels in 2022 showed substantial recovery in September, with 76 of 126 wells indicating normal or above normal conditions (fig. 3B).

Similar to streamflows, the severity of drought effects on groundwater levels in 2022 varied across New England. Water levels were more severely affected by below normal conditions in southern New England, in many cases declining below 2020 water levels in July and August (apps. 1 to 6). For example, the monthly water level at the MA–CYW 13 Cummington, Mass. (422733072532601) USGS monitoring well shows similar conditions in April and May in both 2020 and 2022, but the water level in 2022 declined below 2020 levels from June through August before recovering slightly in September (fig. 5B). In August 2022, the water level at 86 of 108 groundwater monitoring wells was below normal in the three States making up southern New England, with the water level at 14 of these wells representing the 25-year low for August (fig. 3B). In central and northern New England, groundwater levels were only marginally affected, with water levels generally not declining below 2020 conditions (apps. 1 to 6). Of the 18 monitoring wells in central New England and northern Maine, the groundwater level in August was below normal at 9 wells and represented the monthly 25-year low for August at 2 wells.

Paired Streamflow and Groundwater Responses to Precipitation Deficits

Streamflows and groundwater levels at nearby sites are presented to compare their response to precipitation deficits (figs. 6 and 7). Notable water year precipitation deficits in the Hartford, Conn., area began as early as December 2021, and by August 2022, the Hartford area was nearly 10 inches below average (1981–2010) for the water year (fig. 6A; National Oceanic and Atmospheric Administration, 2022a). In April, streamflows at the Salmon River near East Hampton, Conn. (01193500) USGS streamgage and groundwater levels at the CT–MB 32 Marlborough, CT (413535072253701) USGS monitoring well indicated normal to above normal conditions, but by mid-August streamflows and water levels dropped well below normal conditions (fig. 6B). The Marlborough monitoring well recorded monthly 25-year low groundwater levels in June, July, and August. Flows at the Salmon River streamgage began to recover at the end of August because of increased precipitation. The water level at the monitoring well had a delayed response to the precipitation and only had started recovering slightly in September, remaining below normal at the end of September (fig. 6B).

The precipitation deficit was even more substantial in the Boston area for water year 2022, with deficits during the study period exceeding 4 inches in April and declining to more than 14 inches below normal (1981–2010) by the end of September (fig. 7A; National Oceanic and Atmospheric Administration, 2022a). Streamflow at the Nashoba Brook near Acton, Mass. (01097300) USGS streamgage indicated normal or below normal conditions from April through June, with streamflow generally declining to well below normal conditions in July and August; fig. 7B). Water levels at the MA–ACW 158 Acton, MA (422812071244401) USGS monitoring well, however, started April in the upper range of normal conditions likely due to recharge from rainfall in the summer and early fall 2021. The groundwater level at the well in Acton dropped below normal levels in early July and stayed below normal levels through the end of September, whereas the streamflow at Nashoba Brook showed some improvement from rainfall in late August through September (fig. 7B).

Comparison of Streamflow Statistics to Previous Droughts

Because of the differences in lengths, spatial extents, and types of droughts, it is challenging to put droughts into historical context. A streamgage recording a period of record low with 10 years of record has different implications than a streamgage recording a period of record low with 80 years of record. In an effort to compare droughts across the region during the past 30 years, the analysis computed for this study (table 1) indicated the months and years for which the annual 7-day average streamflow was a 30-year low (between 1993 and 2022) for at least 2 months at more than 10 percent of the 78 streamgages in New England. In 2021, all the 30-year lows happened in the three northern New England States, whereas in 2016, all the 30-year lows happened in the three southern New England States.

For 2016, more than 10 percent of the streamgages had 30-year lows from June to September (table 1); however, more than 20 percent of the streamgages had 30-year lows in July 2016 (all in southern New England). In 1995, 30-year lows were recorded in more than 10 percent of the 78 total streamgages in all States from June through September (table 1), and 30-year lows were recorded in more than 20 percent of the total 78 streamgages in June and July.

The data for 2022 are not included in table 1 because 30-year lows were not recorded at more than 10 percent of the 78 streamgages for the year for a 2-month period; however. more than 10 percent of the 78 streamgages recorded 30-year lows during the month of August in 2022, with these lows recorded in Connecticut, Massachusetts, and Vermont. This type of analysis does not include droughts such as the severe 1960s regional drought because it took place more than 30 years ago, nor does it quantify the compounded effects of multiyear droughts, such as for 1961–69 and 1998–2002 because this analysis is based only on annual 7-day average streamflows.