| July 1998 | Flash Flood | Roundup | $200,000 | A slow moving thunderstorm with heavy rain caused water to run over roads on the east end of Roundup. Over one inch of rain fell during a ten minute period. The Roundup Tribune reported that several basements were flooded. |
| May 1999 | Tornado (F0) | Roundup | $25,000 | Eyewitnesses reported seeing a funnel cloud pass over Roundup, and a tornado touchdown north of US12 1 mile east of Roundup. Several trees were downed, a chicken shed was demolished and several sections of wood fencing were destroyed. |
| August 1998 | Thunderstorm Wind | Roundup | $10,000 | A strong thunderstorm downed several trees and a few power lines in and around Roundup. |
| July 2000 | Thunderstorm Wind | Roundup | $3,000 | 2.00 inch hail reported along with broken windows. A hay bale was blown 50 yards. |
| August 1999 | Thunderstorm Wind | Roundup | $1,000 | Wind gusts to 60 mph damaged several large construction signs. |
| July 2025 | Flood | Roundup | - | Spotter reported flooding of drainage ditches and streets. Water flowing up over lawn at hospital in Roundup. |
| July 2025 | Hail | Roundup | - | Quarter size hail reported. |
| July 2025 | Heavy Rain | Roundup | - | Got 1.27 ins in 30 minutes. Flooding on property. |
| June 2019 | Hail | Roundup | - | Quarter size hail was reported 5 miles west of Roundup. |
| May 2018 | Hail | Roundup | - | Seven windows were broken in a home. |
| May 2018 | Hail | Roundup | - | Some broken windows were reported. |
| May 2018 | Hail | Roundup | - | There was widespread golf ball to tennis ball size hail in Roundup. Please see Episode Narrative for this event. |
| May 2018 | Hail | Roundup | - | There was widespread golf ball to tennis ball size hail in Roundup. Please see Episode Narrative for this event. |
| May 2018 | Flash Flood | Roundup | - | Please see Episode Write-up. |
| June 2013 | Hail | Roundup | - | Pea to quarter size hail with winds estimated at 50 mph were reported. |
| June 2013 | Hail | Roundup | - | Pea to quarter size hail was reported. |
| June 2013 | Hail | Roundup | - | Hail was quarter to half dollar size and was accompanied by 50 mph winds. |
| June 2013 | Hail | Roundup | - | Hail was nickel to quarter size and was accompanied by winds estimated at 70 to 80 mph. |
| July 2013 | Thunderstorm Wind | Roundup | - | Thunderstorm wind gusts brought down large tree branches. |
| May 2007 | Hail | Roundup | - | Quarter to half dollar size hail was reported. |
| June 2007 | Thunderstorm Wind | Roundup | - | Several trees and power lines were blown down by 70 mph winds. This resulted in some blocked roadways. |
| June 2007 | Hail | Roundup | - | The golf ball size hail persisted for 20 minutes. |
| June 2007 | Funnel Cloud | Roundup | - | Spotter was looking north towards Roundup and observed a funnel briefly. |
| June 2007 | Hail | Roundup | - | Pea to nickel size hail fell with this storm. |
| July 2006 | Thunderstorm Wind | Roundup | - | Bull Mountain Divide DOT |
| June 2006 | Thunderstorm Wind | Roundup | - | Roof damage |
| August 2006 | Hail | Roundup | - | Grain bin destroyed. |
| July 2004 | Flash Flood | Roundup | - | Flash flooding reported on Horsethief Road. |
| August 2002 | Flash Flood | Roundup | - | Flash flood near Mile Marker 30 caused a motorist to take an alternate route home.Water over U.S. Highway 87. |
| August 2002 | Flash Flood | Roundup | - | Flash flood occurred near Mile Marker 30 on U.S. Highway 87 |
| July 2001 | Flash Flood | Roundup | - | Water continued to cover the roadways and the reservoirs were overflowing. |
| July 2001 | Flash Flood | Roundup | - | Water covered the roadways |
| July 2001 | Thunderstorm Wind | Roundup | - | 80 mph thunderstorm wind gust...trees down in the Bull Mountains |
| July 2001 | Hail | Roundup | - | Hail completed covered the ground |
| July 2001 | Hail | Roundup | - | Hail completly covered the ground |
| July 2001 | Hail | Roundup | - | Nickel size hail two feet deep |
| August 2000 | Thunderstorm Wind | Roundup | - | 60 mph wind resulting in downed trees |
| August 1999 | Flash Flood | Roundup | - | Flash Flooding was reported in the coulees draining into the Musselshell River along the border between Golden Valley and Musselshell Counties. Water 2 to 3 feet deep covered roadways and ripped out fences. |
| August 1999 | Hail | Roundup | - | Half dollar size hail reported. |
| June 1999 | Hail | Roundup | - | Several spotters reported nickel to dime size hail in southern Musselshell County. |
| August 1999 | Hail | Roundup | - | Silver Dollar size hail reported. |
| August 1999 | Hail | Roundup | - | Dime size hail reported near Roundup. |
| June 1999 | Funnel Cloud | Roundup | - | Spotters indicated a funnel cloud on US-87. |
| June 1999 | Thunderstorm Wind | Roundup | - | Musselshell County Sheriff reported 65 mph wind gusts. Several large tree branches and street signs were blown down. |
| June 2024 | Hail | Roundup | - | no account filed |
| July 2020 | Hail | Roundup | - | no account filed |
| July 2020 | Hail | Roundup | - | no account filed |
| July 2020 | Hail | Roundup | - | no account filed |
| June 2018 | Hail | Roundup | - | no account filed |
| May 2018 | Hail | Roundup | - | no account filed |
| May 2018 | Thunderstorm Wind | Roundup | - | no account filed |
| February 2017 | Flood | Roundup | - | no account filed |
| June 2016 | Hail | Roundup | - | no account filed |
| June 2016 | Hail | Roundup | - | no account filed |
| June 2016 | Hail | Roundup | - | no account filed |
| July 2016 | Hail | Roundup | - | no account filed |
| July 2016 | Hail | Roundup | - | no account filed |
| July 2016 | Hail | Roundup | - | no account filed |
| July 2016 | Hail | Roundup | - | no account filed |
| July 2015 | Hail | Roundup | - | no account filed |