81 inches above normal. This ranks as the wettest and 33rd warmest July among 138 years of state records.
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.
July 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 July among 138 years of state records. The only calendar month to bring more rain to Iowa was July 1993 with a statewide average of 10.50 inches while the previous July record was 10.33 inches in 1947. The continued wet weather resulted in widespread flooding along Iowa's rivers. Though not as extreme as the flooding was in 1993 and 2008, it was extensive and long lived. The flooding damaged crops as well as property. The lateness of the flooding meant that farmers were not able to replant and made for total losses on some farms for the growing season. Temperatures warmer than normal was the rule for most of July, 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. Parts of northern and western Iowa came into July needing some rainfall to help planted crops continue to 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 July 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|Little Sioux 12.83 11.69 in Aug. 2007 53 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 July 22. Why wasn’t there record flooding with record June and July rainfall? Certainly there has been plenty of flooding across Iowa during July and some of it in record territory for a few locations in the state. However, so far, flooding had 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 July 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.
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 Jul 18, 5:22 AM CST, 2 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 622 AM CDT SUN JUL 18 2010 .DISCUSSION... BUSY SHIFT WITH DERECHO RACING SWD ACRS THE CWA ATTM. CDFNT MAKING PROGRESS ACRS THE STATE AND WILL PUSH TSRA TO THE SE BY AFTN. LTL TIME SPENT ON FCST OTHER THAN LARGER SCALE FEATURES. MAIN CHNGS TO FCST IS WITH THE QSTNRY FNTL BNDRY REMAINING IN THE AREA THRU THE NEXT SVRL DAYS. HAVE UPPED POPS THRU THE PD WITH PERIODIC TSRA THRU THE NEXT 4 TO 5 DAYS. CONCERN IS FOR TTL RAFL. OTR THEN THE VERY HEAVY RAFL GOING ON AT PRESENT...IT APPEARS RAFL AMTS IN ANY 12 HR PD WILL NOT BE EXCESSIVE...HWVR THE TOTAL BY THE END OF THE WED NGT TO THU TIMEFRAME WILL LIKELY BE SVRL INCHS OVR MOST OF THE CWA. TRIMMED DAYTIME TEMPS BASED ON INC CLOUD COVER AND SHOWER ACTIVITY. && .AVIATION...18/12Z MCV FROM OVERNIGHT CONVECTION IS NOW LOCATED JUST EAST OF KOTM. TSRA WILL EXIT THE AREA WITH VFR CONDS THRU THE DAY. COULD SEE SOME ISOLD TSRA POP UP OVER SRN IA THIS AFTN HOWEVER. NWLY WINDS WILL OVERSPREAD THE TAF SITES BY MID DAY. CDFNT WRN WI INTO SWRN IA WILL PASS SOUTHEAST OF IA TDA AND STALL TO THE SOUTH. TSRA WILL REDEVELOP OVR SWRN IA AND MAY REACH TO NEAR A KDSM-KFOD LINE BY THE END OF PD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE && SHORT TERM...MS JUL 10 LONG TERM...MS JUL 10 AVIATION...MS JUL 10
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 545 AM CDT SUN JUL 18 2010 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-191100- EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO- POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN- WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE- BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER- POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION- CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE- DAVIS- 545 AM CDT SUN JUL 18 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS WILL OCCUR OVER THE SOUTHEAST HALF OF THE AREA THIS MORNING. SEVERE STORMS ARE POSSIBLE EARLY OVER THE FAR SOUTHEAST. SCATTERED THUNDERSTORMS ARE EXPECTED SOUTH OF HIGHWAY 92 THIS AFTERNOON...HOWEVER SEVERE WEATHER IS NOT LIKELY. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED OVER THE SOUTHWEST HALF OF IOWA AFTER MIDNIGHT TONIGHT. SEVERE WEATHER IS NOT LIKELY. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SEVERAL ROUNDS OF THUNDERSTORMS ARE EXPECTED MONDAY THROUGH THURSDAY NIGHT. THE THREAT OF SEVERE WEATHER IS LOW WITH THESE STORMS...HOWEVER HEAVY RAINFALL IS LIKELY. OVER THE COURSE OF THE NEXT FEW DAYS...MOST LOCATIONS CAN EXPECT SEVERAL INCHES OF RAINFALL. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED...HOWEVER RAINFALL REPORTS WOULD BE APPRECIATED.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
501 AM CDT SUN JUL 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0454 AM TSTM WND GST RATHBUN 40.80N 92.89W
07/18/2010 E60 MPH APPANOOSE IA TRAINED SPOTTER
&&
MS JUL 10PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
514 AM CDT SUN JUL 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0455 AM TSTM WND GST MYSTIC 40.78N 92.94W
07/18/2010 E70 MPH APPANOOSE IA AMATEUR RADIO
60 TO 70 MPH WIND WITH PEA SIZED HAIL.
&&
SMALLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
552 AM CDT SUN JUL 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0550 AM FLASH FLOOD KNOXVILLE 41.32N 93.10W
07/18/2010 MARION IA EMERGENCY MNGR
4 FEET OF WATER IN SOME CITY STREETS. CARS STALLED.
0550 AM FLASH FLOOD 6 SE MELCHER-DALLAS 41.18N 93.15W
07/18/2010 MARION IA EMERGENCY MNGR
WATER OVER 103RD AVENUE INTO COLUMBIA NEAR HIGHWAY 14.
&&
SMALLPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
621 AM CDT SUN JUL 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1110 PM HAIL 4 WNW ESTHERVILLE 43.42N 94.91W
07/17/2010 E1.00 INCH EMMET IA TRAINED SPOTTER
MOSTLY DIME TO NICKEL SIZE.
1125 PM TSTM WND DMG RUTHVEN 43.13N 94.90W
07/17/2010 PALO ALTO IA BROADCAST MEDIA
LAWN FURNITURE BLOWN AROUND. ESTIMATED GUSTS TO 50 MPH.
RELAYED BY KICD RADIO.
1129 PM HAIL WALLINGFORD 43.32N 94.79W
07/17/2010 E0.25 INCH EMMET IA BROADCAST MEDIA
RELAYED BY KICD RADIO.
1238 AM HAIL 3 W PLOVER 42.88N 94.68W
07/18/2010 E1.00 INCH POCAHONTAS IA FIRE DEPT/RESCUE
RELAYED BY KICD RADIO
0100 AM TSTM WND GST HUMBOLDT 42.72N 94.22W
07/18/2010 E75.00 MPH HUMBOLDT IA LAW ENFORCEMENT
HUMBOLDT COUNTY SHERIFFS OFFICE REPORTS 70-80 MPH WIND IN
TOWN.
0105 AM TSTM WND GST 1 NW DAKOTA CITY 42.73N 94.21W
07/18/2010 E70.00 MPH HUMBOLDT IA TRAINED SPOTTER
0121 AM TSTM WND GST 5 N FORT DODGE 42.59N 94.18W
07/18/2010 E65.00 MPH WEBSTER IA TRAINED SPOTTER
ESTIMATED 60-70 MPH WINDS. 2 TO 4 INCH DIAMETER TREE
BRANCHES DOWN. ADDITIONAL DAMAGE UNKNOWN DUE TO LOW
VISIBILITY BECAUSE OF VERY HEAVY RAIN.
0128 AM TSTM WND GST EAGLE GROVE 42.67N 93.90W
07/18/2010 M58.00 MPH WRIGHT IA MESONET
0200 AM TSTM WND GST 2 ESE WEBSTER CITY AIRP 42.42N 93.84W
07/18/2010 E60.00 MPH HAMILTON IA TRAINED SPOTTER
NUMEROUS SMALL TREE BRANCHES DOWN.
0200 AM HEAVY RAIN 1 W FORT DODGE 42.51N 94.20W
07/18/2010 M1.70 INCH WEBSTER IA MESONET
FELL IN ONE HOUR...BETWEEN 1 AND 2 AM CDT.
0205 AM TSTM WND GST 2 S BOXHOLM 42.14N 94.11W
07/18/2010 E60.00 MPH BOONE IA EMERGENCY MNGR
HALF INCH HAIL ALSO REPORTED IN BOXHOLM
0223 AM TSTM WND GST BOONE 42.05N 93.88W
07/18/2010 M65.00 MPH BOONE IA AWOS
0225 AM TSTM WND GST 3 SSW BOONE AIRPORT 42.02N 93.87W
07/18/2010 E60.00 MPH BOONE IA NWS EMPLOYEE
0228 AM TSTM WND GST 4 ESE BOONE AIRPORT 42.02N 93.77W
07/18/2010 M72.00 MPH BOONE IA MESONET
0238 AM TSTM WND GST AMES 42.02N 93.63W
07/18/2010 M71.00 MPH STORY IA ASOS
0240 AM TSTM WND GST AMES 42.02N 93.63W
07/18/2010 M60.00 MPH STORY IA TRAINED SPOTTER
0243 AM TSTM WND GST 4 NE AMES AIRPORT 42.03N 93.57W
07/18/2010 M67.00 MPH STORY IA MESONET
0245 AM NON-TSTM WND GST 3 NE AMES AIRPORT 42.03N 93.58W
07/18/2010 E70.00 MPH STORY IA TRAINED SPOTTER
POWER LINES DOWN. SMALL TREE BRANCHES ALSO DOWN.
0246 AM TSTM WND GST 3 W KELLEY 41.95N 93.72W
07/18/2010 E52.00 MPH BOONE IA AMATEUR RADIO
ALSO PEA SIZED HAIL.
0246 AM TSTM WND GST ANKENY 41.72N 93.61W
07/18/2010 E65.00 MPH POLK IA AMATEUR RADIO
ESTIMATED 60-70 MPH WINDS ON NORTH SIDE OF ANKENY.
0250 AM TSTM WND DMG 1 NNW JOHNSTON 41.71N 93.71W
07/18/2010 POLK IA NWS EMPLOYEE
BEAVER DRIVE CLOSED BY CAMP DODGE AS CREWS REMOVE FALLEN
TREE ACROSS ROAD. TIME ESTMIATED.
0257 AM TSTM WND GST 3 NW JOHNSTON 41.72N 93.74W
07/18/2010 M66.00 MPH POLK IA OFFICIAL NWS OBS
NWS OFFICE IN JOHNSTON
0300 AM TSTM WND GST 6 NW DES MOINES 41.64N 93.69W
07/18/2010 M84.00 MPH POLK IA TRAINED SPOTTER
MEASURED GUST. SEVERAL TREES DOWN.
0300 AM HEAVY RAIN 2 NNW POLK CITY 41.79N 93.73W
07/18/2010 M2.36 INCH POLK IA MESONET
FELL IN ONE HOUR...BETWEEN 2 AND 3 AM CDT.
0304 AM TSTM WND GST 1 NNW WAUKEE 41.62N 93.87W
07/18/2010 E65.00 MPH DALLAS IA TRAINED SPOTTER
0305 AM TSTM WND GST 4 NNW ANKENY AIRPORT 41.74N 93.60W
07/18/2010 E70.00 MPH POLK IA TRAINED SPOTTER
NUMEROUS 4-6 INCH DIAMETER TREE LIMBS DOWN.
0305 AM TSTM WND DMG N ANKENY 41.72N 93.61W
07/18/2010 POLK IA LAW ENFORCEMENT
CANOPY AT CASEYS BLOWN DOWN
0308 AM TSTM WND GST 3 SW CLIVE 41.58N 93.80W
07/18/2010 E70.00 MPH DALLAS IA NWS EMPLOYEE
ALSO PEA SIZED HAIL.
0309 AM TSTM WND GST URBANDALE 41.64N 93.74W
07/18/2010 E70.00 MPH POLK IA TRAINED SPOTTER
0314 AM TSTM WND GST DES MOINES INT AIRPORT 41.53N 93.66W
07/18/2010 M60.00 MPH POLK IA ASOS
0318 AM TSTM WND GST ANKENY AIRPORT 41.69N 93.57W
07/18/2010 M53.00 MPH POLK IA AWOS
0320 AM TSTM WND GST DES MOINES INT AIRPORT 41.53N 93.66W
07/18/2010 M61.00 MPH POLK IA ASOS
0325 AM TSTM WND GST 5 NE BONDURANT 41.74N 93.39W
07/18/2010 E60.00 MPH POLK IA TRAINED SPOTTER
SMALL TREE BRANCHES BLOWN DOWN
0326 AM TSTM WND DMG WAUKEE 41.61N 93.86W
07/18/2010 DALLAS IA LAW ENFORCEMENT
LARGE TREES OF UNKNOWN DIAMETER DOWN IN WAUKEE AND
WOODWARD. POWER OUT ACROSS HALF OF WAUKEE.
0328 AM TSTM WND GST WINTERSET 41.34N 94.02W
07/18/2010 E70.00 MPH MADISON IA MESONET
0330 AM TSTM WND DMG WINTERSET 41.34N 94.02W
07/18/2010 MADISON IA LAW ENFORCEMENT
TREES DOWN ... MULTIPLE POWER OUTAGES AND DOWNED
TRANSFORMERS.
0443 AM HEAVY RAIN KNOXVILLE 41.32N 93.10W
07/18/2010 U0.00 INCH MARION IA EMERGENCY MNGR
SOME AREAS OF KNOXVILLE ARE REPORTING STREET FLOODING.
0454 AM TSTM WND GST RATHBUN 40.80N 92.89W
07/18/2010 E60.00 MPH APPANOOSE IA TRAINED SPOTTER
0454 AM NON-TSTM WND GST RATHBUN 40.80N 92.89W
07/18/2010 E60.00 MPH APPANOOSE IA TRAINED SPOTTER
PEA TO SLIGHTLY LARGER HAIL.
0455 AM TSTM WND GST MYSTIC 40.78N 92.94W
07/18/2010 E70.00 MPH APPANOOSE IA AMATEUR RADIO
60 TO 70 MPH WIND WITH PEA SIZED HAIL.
0550 AM FLASH FLOOD 6 SE MELCHER-DALLAS 41.18N 93.15W
07/18/2010 MARION IA EMERGENCY MNGR
WATER OVER 103RD AVENUE INTO COLUMBIA NEAR HIGHWAY 14.
0550 AM FLASH FLOOD KNOXVILLE 41.32N 93.10W
07/18/2010 MARION IA EMERGENCY MNGR
4 FEET OF WATER IN SOME CITY STREETS. CARS STALLED.
&&
SMALLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
725 AM CDT SUN JUL 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 AM TSTM WND GST 1 W RATHBUN 40.80N 92.91W
07/18/2010 M72 MPH APPANOOSE IA TRAINED SPOTTER
WIND GUST REPORTED BY HAM RADIO OPERATOR.
&&
JHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
807 AM CDT SUN JUL 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 AM TSTM WND DMG 2 ENE URBANDALE 41.64N 93.71W
07/18/2010 POLK IA NWS EMPLOYEE
TELEPHONE POLE SNAPPED NEAR THE TOP. POWER IN THE AREA IS
REPORTED TO BE OUT. TIME ESTIMATED.
&&
JHThe national radar mosaic for the moment the first event began.
10 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, July 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: 238702, 238708, 238709, 238710, 238703, 238705, 238711, 238706, 238704, 238707.