| May 1998 | Thunderstorm Wind | Harlan | $70,000 | Two walls at the landfill destroyed. |
| May 1998 | Thunderstorm Wind | Harlan | $60,000 | Storage building destroyed. |
| June 2014 | Flash Flood | Harlan | $50,000 | Local law enforcement reported that many county roads had water flowing across them in low spots. There was also street flooding reported in the city of Harlan. |
| July 2010 | Thunderstorm Wind | Harlan | $20,000 | Thunderstorm winds estimated at 55 to 60 mph downed a large tree which crushed the roof of a house in the Harlan area. Time was estimated by radar. |
| May 2024 | Funnel Cloud | Harlan | - | The office received a public report of a funnel clouds 3 miles southwest of Harlan, near 900th Street and Juniper Road. |
| May 2024 | Thunderstorm Wind | Harlan | - | A photo was relayed to the office of a tree that was blown ontop of a house. At the same time, a personal weather station in town recorded a gust of 60 miles per hour. It was likely that the wind gust the blew the tree down on the house was stronger than this. |
| May 2024 | Thunderstorm Wind | Harlan | - | A 64 miles per hour wind gust was measured on a personal weather station. |
| May 2024 | Thunderstorm Wind | Harlan | - | A 65 miles per hour wind gust was measured by a personal weather station. |
| May 2024 | Hail | Harlan | - | The office received a report from the public of quarter sized hail on the northeast side of Harlan, Iowa. |
| May 2024 | Hail | Harlan | - | The office received a report from the 911 Call Center of 2 inch hail that had fallen 3 miles north of Harlan, Iowa. |
| June 2024 | Thunderstorm Wind | Harlan | - | A 72 miles per hour wind gust was measured on a personal weather station 2 miles east of Harlan. |
| June 2024 | Hail | Harlan | - | The office received a report of quarter to golf ball sized hail from the public. |
| June 2024 | Thunderstorm Wind | Harlan | - | The office received a public report of a 62 miles per hour wind gust. This wind gust was accompanied by quarter to golf ball sized hail (this has been put as a separate event given the different event type). |
| July 2023 | Thunderstorm Wind | Harlan | - | Public reported a semi blown over and part of roof blown off a building. |
| May 2022 | Hail | Harlan | - | Trained spotter reported 1 inch hail. |
| July 2022 | Thunderstorm Wind | Harlan | - | Trained spotter reported a measured wind gust of 61 mph and several 2-4 diameter tree limbs down. |
| December 2021 | Thunderstorm Wind | Harlan | - | Harlan AWOS measured a peak wind gust of 72 mph. |
| July 2021 | Thunderstorm Wind | Harlan | - | Law enforcement reported trees down. |
| May 2020 | Thunderstorm Wind | Harlan | - | Trained spotter estimated wind speeds at 71 MPH. |
| July 2019 | Thunderstorm Wind | Harlan | - | Officials estimated winds were 70 mph or higher. |
| June 2018 | Thunderstorm Wind | Harlan | - | A storm spotter estimated a 60 mph wind gust in Harlan. |
| May 2017 | Thunderstorm Wind | Harlan | - | A 52 Knot wind gust was measured at the Harlan Airport AWOS. |
| July 2016 | Thunderstorm Wind | Harlan | - | The emergency manager reported that a tree fell on a car along Highway 59 just to the north of Harlan. There were no injuries reported in the vehicle. |
| June 2014 | Hail | Harlan | - | Numerous reports of large hail were received in and just to the south of the city of Harlan. The hail ranged from around quarter size to 3 inches in diameter. The hail was responsible for damage to windows, cars and roofs in and around town. |
| June 2014 | Flash Flood | Harlan | - | Street flooding was widespread in the city of Harlan. Water was also reported across many county roads outside of town as well. |
| June 2013 | Thunderstorm Wind | Harlan | - | The bowing thunderstorm segment that began in Omaha raced through the Harlan area bringing a measured wind gust of 75 mph at the Harlan Awos. Tree and building damage was noted in town. |
| June 2011 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts were measured at 58 mph by the Awos in Harlan at 835 pm CDT, while a spotter estimated a wind gust about that same magnitude in the area at 828 pm. |
| September 2011 | Thunderstorm Wind | Harlan | - | The Awos near Harlan measured a thunderstorm wind gust of 83 mph. |
| August 2011 | Thunderstorm Wind | Harlan | - | Thunderstorm winds were measured at 65 mph a few miles northwest of Harlan. The winds flattened grain bins in the area and a couple of outbuildings were destroyed. A thousand gallon propane tank was moved around 10 feet by the winds. |
| June 2010 | Thunderstorm Wind | Harlan | - | A thunderstorm wind gust of 61 mph was measured by the Awos at the Harlan airport. The winds downed several large tree limbs in the area. |
| June 2009 | Thunderstorm Wind | Harlan | - | A spotter estimated thunderstorm wind gusts around 60 mph in the Harlan area. |
| July 2009 | Thunderstorm Wind | Harlan | - | Thunderstorm winds estimated at 60 mph downed a few trees and power lines from west of Harlan into town. |
| June 2009 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts estimated at over 60 mph damaged a farm outbuilding near Harlan. |
| May 2008 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts estimated at 60 mph blew a large tree onto a home. |
| July 2008 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts were measured at 60 mph by weather equipment at a Coop observers house 1 mile north of Harlan and at 68 mph by the Awos at the Harlan airport. The strong winds downed some large tree limbs in town. |
| June 2007 | Hail | Harlan | - | The hail was accompanied by 2.2 inches of rain that fell in less than 1 hour. |
| September 2007 | Thunderstorm Wind | Harlan | - | Thunderstorm winds estimated at around 60 mph knocked a few large tree limbs onto power lines causing some brief power outages in town. |
| July 2007 | Thunderstorm Wind | Harlan | - | Thunderstorm winds estimated at around 60 mph downed a few small trees and some 3 to 4 inch in diameter tree limbs across town. |
| September 2006 | Thunderstorm Wind | Harlan | - | Emergency management estimated thunderstorm winds gusted to 60 mph. |
| July 2005 | Thunderstorm Wind | Harlan | - | A thunderstorm wind gust of 62 mph was recorded by the Harlan AWOS. |
| May 2004 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts of 70 mph were measured by the AWOS in Harlan. This was from a storm that apparently merged with the storm that developed just to the southwest and produced the tornado that tracked across the Walnut area. |
| May 2004 | Tornado (F0) | Harlan | - | A tornado tracked south of Harlan near F-58 and Juniper Road according to emergency management. The tornado was also seen from near the Walnut area in extreme northern Pottawattamie county. The tornado apparently remained in open country and caused little or no damage. |
| July 2003 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts over over 60 mph downed trees and power lines from Harlan to Elk Horn. |
| April 2002 | Thunderstorm Wind | Harlan | - | A thunderstorm wind gust of 63 mph was recorded by the Harlan AWOS. |
| June 2002 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gusts downed large tree limbs and power lines in Harlan. |
| June 2001 | Thunderstorm Wind | Harlan | - | Cooperative observer measured a thunderstorm wind gust of 71 mph. |
| August 2001 | Thunderstorm Wind | Harlan | - | Wind equipment measured a 88 mph wind gust which blew a tree onto a road. |
| June 2000 | Thunderstorm Wind | Harlan | - | One inch hail and thunderstorm winds over 60 mph did some damage in the Harlan area. |
| June 2000 | Hail | Harlan | - | Reported by a cooperative observer. |
| August 2000 | Thunderstorm Wind | Harlan | - | Thunderstorm wind gust estimated at 60 mph by a trained storm spotter. |
| May 1998 | Thunderstorm Wind | Harlan | - | Large tree limbs downed. |
| May 1998 | Thunderstorm Wind | Harlan | - | Roof blown off a building. |
| July 2019 | Hail | Harlan | - | no account filed |
| July 2016 | Thunderstorm Wind | Harlan | - | no account filed |
| April 2014 | Hail | Harlan | - | no account filed |
| June 2014 | Thunderstorm Wind | Harlan | - | no account filed |
| June 2013 | Hail | Harlan | - | no account filed |
| May 2011 | Hail | Harlan | - | no account filed |
| August 2011 | Hail | Harlan | - | no account filed |
| April 2010 | Hail | Harlan | - | no account filed |