81 inches above normal. This ranks as the wettest and 33rd warmest June among 138 years of state records and set the stage for significant river flooding.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DMX wrote it up.
June 2010 temperatures averaged 71.4 or 1.6 above normal while precipitation totaled 10.45 inches or 5.81 inches above normal. This ranks as the wettest and 33rd warmest June among 138 years of state records and set the stage for significant river flooding. The only calendar month to bring more rain to Iowa was July 1993 with a statewide average of 10.50 inches while the previous June record was 10.33 inches in 1947. The current preliminary total could vary by about plus or minus 0.15 inches when all data becomes available over the next several weeks, thus these rankings could change. Warmer than normal temperatures were the rule for most of June, as has been the case across Iowa for much of the past four months. Cooler than normal weather was restricted to only the 7th, 10th, 13th, 15th, 24th and 28th-30th. Monthly temperature extremes varied from morning lows of 46 at Sheldon on the 3rd and at Cresco and Elkader on the 29th to an afternoon high of 95 at Onawa on the 26th. Heat indices reached as high as 107 at Des Moines on the 22nd and at Burlington on the 23rd. As for rainfall, parts of northern and western Iowa came into June needing some rainfall to help newly planted crops develop. They, and all of the rest of Iowa, got much more than they needed. Rainfall was very frequent throughout the month. Des Moines, Johnston and Indianola all reported 22 days with measurable rain during the month. The following locations set records for most rain in a single calendar month:
City June 2010 (inches) Old Record Period of Record|Indianola 16.86 15.26 in Jun. 1947 123 years|Guthrie Center 14.92 14.16 in May 1903 113 years|Pella 14.71 13.95 in Aug. 2007 86 years|Hampton 14.28 14.15 in Sep. 1965 117 years|Ankeny 14.27 12.87 in Aug. 1993 60 years|Montezuma 13.56 11.83 in Aug. 1993 66 years|Cherokee 13.11 12.90 in Sep. 1926 91 years|The least rain reported in the state was 5.44 inches at Sidney, but even this amount was 1.22 inches above normal. Unofficial totals were as high as 20.81 inches near Rowan in Wright County where an amazing total of 3.99 inches fell in one hour on the night of June 22. Why wasn’t there record flooding with record June rainfall? Certainly there has been plenty of flooding across Iowa during June and some of it in record territory for a few locations in the state. However, so far through June, flooding has not been as extensive or severe as in 2008 or 1993. The reasons for this are several. First, the past four months have been much warmer (about 6 ) than the same months in 1993 and 2008. The result is that there has been about 20% more evaporation to help dry things between rain events. Second, spring rainfall averaged near normal in 2010 in contrast to much more precipitation in 1993 and 2008. Third, with a few local exceptions, the rainfall in June 2010 has been distributed fairly evenly across the state and through the month. This helps to spread the water out more evenly in space and time so as to reduce the magnitude of the flood crests. (Explanation provided by Iowa State Climatologist Harry Hillaker.) During the first two weeks of the month, repeated thunderstorm activity rolled across the state. The central and south was hit especially hard and is where the greatest flooding occurred. At this point, many areas have experienced a significant period of flooding and farm fields remain unplanted. Heavy rainfall once again pushed many rivers of central and southern Iowa several feet above flood stage. Flooding downstream of the Red Rock Reservoir resulted in major flooding in the Ottumwa area. Evacuations were required. Three hundred residents of a mobile home park wre evatuated near Ottumwa. The last two times this park had to be evacuated were during the flooding periods of 2008 and 1993.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Des Moines, IA wrote its last area forecast discussion before the first event at Jun 12, 2:29 AM CST, 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 329 AM CDT SAT JUN 12 2010 .SHORT TERM /TODAY/... FOR THE THIRD MORNING IN A ROW...A LARGE CONVECTIVE SYSTEM WILL MOVE FROM NEBRASKA IN IOWA PRODUCING VERY HEAVY RAINFALL. IN ADDITION...A QUASI STATIONARY BOUNDARY NEAR THE HIGHWAY 34 CORRIDOR WILL BE A FOCUS FOR CONVECTION DURING THE MORNING. SHEAR IS RELATIVELY WEAK ACRS THE STATE WITH 500MB WINDS OF 5 TO 10 KTS...SO SEVERE WEATHER APPEARS RELATIVELY MINIMAL. HOWEVER...AMPLE MOISTURE IS IN PLACE ALONG WITH DEEP WARM CLOUD LAYERS AND WARM PCPN PROCESSES LEADING TO EFFICIENT RAIN PRODUCERS. ONGOING FFA WILL BE KEPT IN TACT AS LARGE CONVECTIVE COMPLEX MOVES INTO THE STATE. GRIDS HAVE LIKELY TO CATEGORICAL POPS THROUGH THE MORNING FOR THIS ONGOING CONVECTION WITH SCATTERED WORDING THIS AFTERNOON AS EVOLUTION OF THE SYSTEM AND SUBSEQUENT CONVECTION REMAINS MURKY. TEMPS ALSO PROBLEMATIC GIVEN CLOUDS AND RAINFALL DURING THE DAY SO WL STICK CLOSE TO GUIDANCE. .LONG TERM /TONIGHT THROUGH FRIDAY/... MODELS OF LITTLE HELP FOR THE NEXT FEW DAYS AS MESOSCALE DOMINATES CURRENT WX REGIME. SUBJECTIVE SFC ANALYSIS AT 06Z SHOWS BOUNDARY FROM NEAR KOMA TO JUST SOUTH OF KDSM TO NEAR KDBQ. WEAK SFC LOWS CONTINUE TO TRACK ALONG IT. VERY WARM AND HUMID ALONG THE BOUNDARY AND MUCH COOLER AND DRIER NORTH. A SECONDARY COOL FRONT LIES ALONG THE MN DAKOTAS BORDER AND NOW CATCHING UP WITH THE TROUGH THAT LIES ACROSS THE PLAINS NOW. UPPER LEVEL PATTERN SUGGESTS THAT THREAT FOR MODERATE TO HEAVY RAINFALL WILL CONTINUE IN PART THROUGH MID TO END OF WEEK...WITH DETAILS OF HOW MESOSCALE MODULATES THE FLOW A DAILY GRIND FOR NOW. H700 SHOWS 3 DISTINCT WAVES WHICH WILL AFFECT THE REGION AGAIN TNT THROUGH MONDAY. MODELS DO HINT AT COOLER AND DRIER AIR MASS TO ARRIVE ON TUESDAY FOR ABOUT 24 TO 30 HOURS BEFORE ANOTHER WAVE PULLS SOUTHERN AIR MASS AND POTENTIAL MCS BACK ACROSS THE AREA AGAIN FOR WED NIGHT AND THURSDAY. WITH SUBTROPICAL HIGH ANCHORED OVER THE SOUTHEAST FOR MUCH OF THE WEEK...LITTLE CHANGE IN PRECIP POTENTIAL EXPECTED. GEM IS A BIT MORE AGGRESSIVE WITH TAKING THE LATE WEEK SYSTEM FARTHER NORTH. IN THE SHORTER TERM...WITH H850 MOISTURE LEVELS OF +20C DEWPOINTS FROM CENTRAL KS SOUTH TO WESTERN TX AND LARGE AREA OF +15C DEW POINTS COVERING MOST OF THE EAST US... A LOT OF WET WX TO COME. GENERAL FEELING IS THAT ONCE THIS DUAL MCS WORKS ITS WAY EAST BY TONIGHT...THE SFC BOUNDARY WILL GRADUALLY SHIFT SOUTH FOR SUNDAY AND INTO MONDAY...KEEPING HIGHER POPS ACROSS THE SOUTH AT THAT TIME. ANOTHER WAVE APPROACHES ON MONDAY NIGHT AND EARLY TUESDAY AND HAVE BUMPED POP UP ONCE AGAIN. TEMPS WARM THE NEXT 2 DAYS AND THEN HAVE LOWERED HIGHS A BIT MOVING FORWARD. && .AVIATION... 12/06Z...LITTLE CHANGE FROM PREVIOUS 18Z AND 00Z THINKING. EXPECT CONVECTIVE COMPLEX OVER NEBRASKA TO CONTINUE MOVING SLOWLY EASTWARD INTO IA WITH POSSIBLY ADDITIONAL DEVELOPMENT FARTHER EAST INTO IA BEFORE IT GETS HERE. THUS HAVE HIGH CONFIDENCE THAT CONVECTION AND THUNDER WILL AFFECT SITES LATE TONIGHT AND INTO SAT MORNING...BUT LITTLE CONFIDENCE REGARDING TIMING AT ANY PARTICULAR LOCATION. THUS WILL STAY WITH VICINITY WORDING UNTIL TIMING BECOMES CLEARER. SIMILAR THINKING WITH VFR VS MVFR. CIGS WILL LIKELY DROP TO MVFR OR LOWER WITH STORM OCCURRENCES...BUT PREDICTABILITY TOO LOW TO INCLUDE AT THIS TIME. WINDS WILL BE DIFFICULT TO PIN DOWN AS WELL WITH MEANDERING FRONT EXTENDED SW-NE ACROSS IA AT 06Z AND EXPECTED TO MOVE LITTLE. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH EXTENDED THROUGH 21Z ADAMS-ADAIR-AUDUBON-CALHOUN- CARROLL-CASS-CRAWFORD-EMMET-GREENE-GUTHRIE-HUMBOLDT-KOSSUTH- PALO ALTO-POCAHONTAS-RINGGOLD-SAC-TAYLOR-UNION-WEBSTER && SHORT TERM...COGIL LONG TERM...REV AVIATION...SMALL
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 406 PM CDT FRI JUN 11 2010 IAZ004-005-015-023-024-033>035-044>046-057-058-070-071-122115- EMMET-KOSSUTH-PALO ALTO-POCAHONTAS-HUMBOLDT-SAC-CALHOUN-WEBSTER- CRAWFORD-CARROLL-GREENE-AUDUBON-GUTHRIE-CASS-ADAIR- 406 PM CDT FRI JUN 11 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...THIS AFTERNOON AND TONIGHT ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING. A LARGER AREA OF THUNDERSTORMS AND HEAVY RAIN IS EXPECTED TO MOVE THROUGH LATE TONIGHT. DAMAGING WINDS AND SMALL HAIL ARE THE MAIN THREATS. RAINFALL RATES IN EXCESS OF ONE INCH PER HOUR COULD LEAD TO FLASH FLOODING. A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA. PLEASE REFER TO THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES FOR FURTHER DETAILS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORMS AND HEAVY RAIN ARE LIKELY EARLY SATURDAY. A FLASH FLOOD WATCH REMAINS IN EFFECT SATURDAY MORNING. THE THREAT OF DAMAGING WINDS DURING THIS TIME IS LOW. THUNDERSTORM CHANCES CONTINUE INTERMITTENTLY THROUGHOUT THE WEEKEND AND INTO NEXT WEEK. THERE THREAT OF SEVERE WEATHER APPEARS FAIRLY MINIMAL AT THIS TIME FOR THE WEEKEND...AND IT IS TOO EARLY TO DETERMINE THE CHANCE OF SEVERE WEATHER FOR NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TONIGHT OR SATURDAY. IAZ006-007-016-017-025>028-036>039-047>050-059>062-072>075-081>086- 092>097-122115- WINNEBAGO-WORTH-HANCOCK-CERRO GORDO-WRIGHT-FRANKLIN-BUTLER-BREMER- HAMILTON-HARDIN-GRUNDY-BLACK HAWK-BOONE-STORY-MARSHALL-TAMA-DALLAS- POLK-JASPER-POWESHIEK-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION- CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE- DAVIS- 406 PM CDT FRI JUN 11 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...THIS AFTERNOON AND TONIGHT ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING. A LARGER AREA OF THUNDERSTORMS AND HEAVY RAIN IS EXPECTED TO MOVE INTO THE REGION LATE TONIGHT. DAMAGING WINDS AND SMALL HAIL ARE THE MAIN THREATS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORMS AND HEAVY RAIN ARE LIKELY EARLY SATURDAY. THE THREAT OF DAMAGING WINDS DURING THIS TIME IS LOW...BUT LOCALLY HEAVY RAIN COULD LEAD TO FLOODING. THUNDERSTORM CHANCES CONTINUE INTERMITTENTLY THROUGHOUT THE WEEKEND AND INTO NEXT WEEK. THERE THREAT OF SEVERE WEATHER APPEARS FAIRLY MINIMAL AT THIS TIME FOR THE WEEKEND...AND IT IS TOO EARLY TO DETERMINE THE CHANCE OF SEVERE WEATHER FOR NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TONIGHT OR SATURDAY. MOYER
The national radar mosaic for the moment the first event began.
15 flood. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2010Every state in 2010This day in weather historyWarnings in Iowa, June 2010
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 230798, 230792, 230796, 230793, 230784, 230797, 230788, 230794, 230791, 230795, 230790, 230781, 230785, 230786, 230787.