NOAA: 12-month precipitation record hits all-time high for the third month in a row, U.S.

Heavy rainfall during the month of June added to another record-breaking 12 months of precipitation for the contiguous U.S – the third consecutive time in 2019 (April, May and June) the past 12-month precipitation record has hit an all-time high.

The June precipitation total for the contiguous U.S. was 83.82 mm (3.30 inches), 9.39 mm (0.37 inch) above average, and ranked in the upper third of the 125-year period of record. For the year-to-date (July 9), the precipitation total was 483.87 mm (19.05 inches), 94.99 mm (3.74 inches) above average, and the wettest such period in the 125-year record.

Average precipitation across the contiguous U.S. for July 2018–June 2019 was 961.64 mm (37.86 inches), 200.66 mm (7.90 inches) above average, and broke a record, exceeding the previous all-time 12-month period on record set at the end of May.

The previous all-time 12-month record was 958.08 mm (37.72 inches) and occurred from June 2018–May 2019.

Prior to that record, the all-time 12-month record was 922.27 mm (36.31 inches) during May 2018–April 2019. The previous July–June record was 891.79 mm (35.11 inches) and occurred from July 1982–June 1983. 

Above- to much-above-average precipitation was observed from the Deep South, through the Mississippi and Ohio valleys and along much of the East Coast. Kentucky ranked third wettest, Ohio was fifth wettest and Tennessee ranked eighth wettest for June.

Flooding persisted along many of the major river systems and their tributaries across the central U.S. including the central and lower Mississippi River, the Missouri River, as well as the Illinois River.

As astronomical spring transitioned into summer in the Northern Hemisphere on June 21, an intense low pressure system brought more than a foot of snow to parts of the northern and central Rockies. 

Below-average precipitation was observed across six states in the West as well as North and South Dakota. 

According to the July 2 U.S. Drought Monitor report, 3.2% of the contiguous U.S. was in drought, down from 5.3% at the beginning of June.

Drought conditions worsened across parts of the Pacific Northwest and Puerto Rico but improved across much of the Southeast, parts of the Southwest, as well as across Hawaii.

Source: NOAA/NCDC

Featured image credit NOAA