Hail History

Hail history for Thornton, Colorado

NOAA hail reports in and within about 5 km (3 miles) of Thornton since 1955, with preliminary reports to November 3, 2026.

Readout · Thornton

Last hail
Jun 17, 2025
0.75 in, penny size
Hail days, last 5 years
7
since Nov 3, 2021 · 28 reports
Largest ever
2.50 in
tennis ball · Jun 18, 2018

81 reports on 37 days since 1955 · #22 of 183 Colorado places

Hail map · Thornton

Thornton Broomfield Westminster Commerce City Brighton Erie Dacono Denver 10 mi
  • Under 1 in
  • 1–1.75 in
  • 1.75–2.5 in
  • 2.5–4 in
  • 4 in +
  • No size
81 most recent reports with a location; Adams County is shaded. Open street map

For homeowners

Roof damage after hail? Get a free inspection

Hail bruises shingles and cracks seals in ways you can't see from the ground, and most insurers set a claim deadline after the storm. The latest hail report in Thornton is from June 17, 2025. A local roofer can check and document it at no cost.

Phone line opening soon

What would a claim cost you? Try the hail claim calculator

Preview: this form is not connected yet. Nothing you enter is sent or stored.

Roofer? Get hail alerts for your area with StormScope

What the record says about Thornton

The latest hail report in and around Thornton is from June 17, 2025, 0.75 in (penny size). Since November 3, 2021 there have been 7 separate hail days; the biggest stones in that time were 2.00 in on May 30, 2024.

Over the 20 years 2006–2025, Thornton logged 53 reports on 19 hail days, about 2.6 reports a year. That is 3.3 times the median Colorado town on this site (0.8 a year) and ranks #22 of 183 Colorado cities and towns on this site for all-time reports. Thornton accounts for 16% of the 503 reports filed in Adams County.

7% of reports with a size were 2 inches (hen egg) or larger, against 8% for the median Colorado town on this site. The largest hail on record here is 2.50 in (tennis ball) on June 18, 2018 near 3.36 NW Henderson.

Reports were up 153% in 2016–2025 (38) compared with 2006–2015 (15). The busiest year was 2024, with 14 reports on 3 days. Hail here peaks in May (33% of reports); 72% fall between April and June.

Reports a year 2006–2025 average

  • Thornton 2.6
  • Adams County 12.8
  • Median Colorado town on this site 0.8

Hail days 2006–2025

  • Thornton 19
  • Adams County 89
  • Median Colorado town on this site 11

Share 2 in or larger of sized reports

  • Thornton 7%
  • Adams County 8%
  • Median Colorado town on this site 8%

Hail over time

051015 1955: 1 reports, largest 2.50 in 1960 1970 1980 1983: 3 reports, largest 1.75 in 1984: 1 reports, largest 0.75 in 1986: 1 reports, largest 1.75 in 1990: 1 reports, largest 1.00 in 1990 1991: 2 reports, largest 2.00 in 1996: 2 reports, largest 1.25 in 1997: 1 reports, largest 2.00 in 2000 2001: 2 reports, largest 1.75 in 2002: 1 reports, largest 0.75 in 2004: 5 reports, largest 1.75 in 2005: 8 reports, largest 1.00 in 2008: 1 reports, largest 1.00 in 2009: 1 reports, largest 1.25 in 2010: 7 reports, largest 1.75 in 2010 2011: 3 reports, largest 1.00 in 2014: 3 reports, largest 1.00 in 2016: 2 reports, largest 1.00 in 2018: 5 reports, largest 2.50 in 2020 2021: 3 reports, largest 1.00 in 2023: 6 reports, largest 1.25 in 2024: 14 reports, largest 2.00 in 2025: 8 reports, largest 1.25 in
Reports per year, 1955–2026. Bar colour shows the largest hail that year. Reporting grew sharply after the mid-1990s, so early decades undercount.
0102030 Jan Feb Mar April: 4 reports (5%) Apr May: 27 reports (33%) May June: 27 reports (33%) Jun July: 11 reports (14%) Jul August: 11 reports (14%) Aug September: 1 reports (1%) Sep Oct Nov Dec
All 81 reports by calendar month.
Reports per month, 2017–2026. Darker cells had more reports.
YearJanFebMarAprMayJunJulAugSepOctNovDecTotal
2026 0
2025 8 8
2024 113 14
2023 213 6
2022 0
2021 3 3
2020 0
2019 0
2018 5 5
2017 0

Hail days since Nov 3, 2021

DateReportsLargestStorm page
Jun 17, 2025 8 1.25 in —
Jul 20, 2024 1 0.75 in —
Jul 7, 2024 2 0.75 in —
May 30, 2024 11 2.00 in —
Aug 3, 2023 3 1.25 in —
Jun 21, 2023 1 1.00 in —
May 9, 2023 2 1.00 in —

Largest hail on record

Largest hail reports in Thornton
Date Size Location County Time · source
Jun 18, 2018 2.50 intennis ball 3.36 NW Henderson Adams 19:49 local · NCEI
Sep 19, 1955 2.50 intennis ball — Adams 16:00 local · NCEI
May 30, 2024 2.00 inhen egg 2.14 SSW Henderson Adams 21:02 local · NCEI
Jun 18, 2018 2.00 inhen egg 2.96 NNE Northglenn Adams 19:47 local · NCEI
Jun 12, 1997 2.00 inhen egg Henderson Adams 14:30 local · NCEI

Sizes filed before 1996 are often rough estimates (round numbers like 7.00 or 8.00 in) without an exact spot; they are shown as NOAA filed them.

Size of every report

Most recent reports

Most recent hail reports in Thornton
Date Size Location County Time · source
Jun 17, 2025 0.75 inpenny 2.61 NE Thornton Adams 13:14 local · NCEI
Jun 17, 2025 1.00 inquarter 1.48 NNE Thornton Adams 13:11 local · NCEI
Jun 17, 2025 1.00 inquarter Northglenn Adams 13:10 local · NCEI
Jun 17, 2025 1.00 inquarter 4.92 NNW Henderson Adams 03:21 local · NCEI
Jun 17, 2025 1.00 inquarter 2.23 WNW Henderson Adams 03:21 local · NCEI
Jun 17, 2025 0.75 inpenny 2.53 WNW Henderson Adams 03:18 local · NCEI
Jun 17, 2025 1.00 inquarter 2.53 WNW Henderson Adams 03:17 local · NCEI
Jun 17, 2025 1.25 inhalf dollar 2.74 WNW Henderson Adams 03:15 local · NCEI
Jul 20, 2024 0.75 inpenny 1.48 NNE Thornton Adams 19:41 local · NCEI
Jul 7, 2024 0.75 inpenny 1.48 NNE Thornton Adams 14:55 local · NCEI
Jul 7, 2024 0.75 inpenny Northglenn Adams 14:51 local · NCEI
May 30, 2024 2.00 inhen egg 2.14 SSW Henderson Adams 21:02 local · NCEI

Hail history near Thornton

Questions about hail in Thornton

How often does it hail in Thornton, Colorado?

81 hail reports have been logged in and within about 5 km (3 miles) of Thornton since 1955. Over the 20 years 2006–2025 that averages 2.6 reports a year. That ranks #22 of 183 Colorado places by number of reports.

When is hail season in Thornton?

Most reports come in May, June, July. May alone accounts for 33% of all reports.

What is the largest hail recorded in Thornton?

2.50 in (tennis ball size) on June 18, 2018 near 3.36 NW Henderson. 7% of reports here were 2 inches or larger.

When did it last hail in Thornton?

The most recent report in this data is from June 17, 2025 (0.75 in). Final NOAA data runs to July 31, 2026; preliminary NWS reports run to November 3, 2026.

How many hail storms has Thornton had in the last five years?

7 separate days with hail reports since November 3, 2021, adding up to 28 reports. The most recent was June 17, 2025.

Where does this hail data come from?

Hail reports come from the NOAA NCEI Storm Events Database, which the National Weather Service compiles from spotter, public, law enforcement and media reports. Recent days use preliminary NWS Local Storm Reports via the Iowa Environmental Mesonet until NOAA publishes final data. Only reported hail is counted, so areas with fewer people tend to have fewer reports.