Minor to locally moderate flooding occurred across the northeast side of the HSA from the 18th to 23rd. Minor flooding occurred along much of the Mississippi River from Wabasha MN to Guttenberg IA on the 21st to the 31st. May 2017 for the La Crosse HSA had below to much above normal precipitation and below normal temperatures.

Heavy rains of 3 to locally 6 inches fell across portions of southeast MN into central WI from the 15th to the 20th. These rains coupled with very wet soils from the from the above normal March and April precipitation, produced minor to moderate flooding on portions of the Trempealeau, Black , Yellow and Wisconsin Rivers of western into central WI from the 17th to 23rd. Some flash flooding occurred in parts of southeast MN where the rain totals were heaviest. Flow from these rivers, along with inflows from rivers north of the HSA and already high flows, then produced strong within bank rises to minor flooding on the Mississippi River from Lake City MN to Guttenberg IA during the 21st to 31st.

May 2017 rainfall in the La Crosse HSA ranged from below normal across portions of the west, southeast and east ends of the HSA, to above and much above normal over the central and north-central sections. A slow moving low brought moderate to locally heavy rain to much of the HSA on the 1st. A low and stationary front brought light to moderate rains to much of the HSA on the 8th, with lingering light rain showers on the 9th. Light to moderate rain fell across the south half of the HSA on the 10th. A series of lows and fronts brought locally heavy rains to much of the central and north parts of the HSA from the 15th to the 17th, with another low producing moderate rains across much of the HSA on the 20th. As much as three-fourths of the month’s rainfall occurred during this period. Light to locally moderate rains fell across much of the HSA from the 21st to 23rd. As cooler air settled over the HSA for the last week of the month, scattered, mainly light rain showers were common from the 24th to 30th.

May rainfall normally ranges from around 3.5 inches across the northeast half of the HSA, to near 4.5 inches across the northeast IA portion of the HSA. Totals this month ranged from 65 to 85 percent of normal across parts of the west and southeast ends, to 150 to 250 percent of normal across portions of the central and north-central sections of the HSA. Most May totals were 90 to 130 percent of normal. Extreme totals recorded for the month ranged from 2.13 inches at Oelwein Fayette Co. IA and 2.66 inches at L/D 10 near Guttenberg IA, to 9.23 inches near Elba in Olmsted Co. MN and 9.38 inches near Altura in Winona Co. MN.

May 2017 temperatures averaged 54 to 59 degrees. This was 1 to 2.5 degrees below the normals. Temperatures were much below normal on the 1st, with a little light snow or flurries falling at some locations to start the month. The 2nd to the 12th was a period of near to below normal temperatures. Above to much above normal temperatures occurred from the 13th to the 17th, followed by below and much below normal readings from the 18th to the 24th. The last week of the month saw near to below normal temperatures. Extremes for the month ranged from lows in the mid 20s to mid 30s on the morning of the 3rd, to highs in the upper 70s to upper 80s on the 16th.

Flows in the rivers and streams of the HSA were above to much above normal during this May. The continued above normal rains and wet soils impacted spring field work and planting across parts of the HSA. The below normal temperatures in May slowed crop growth and development, but most were near to only a few days behind average at the end of the month.