Thunderstorms in Boulder, CO
| Year | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | YEAR |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1971 | 0 | 0 | 0 | 4 | 7 | 16 | 13 | 6 | 4 | 3 | 0 | 0 | 53 |
| 1972 | 0 | 0 | 1 | 0 | 6 | 17 | 13 | 12 | 7 | 1 | 0 | 0 | 57 |
| 1973 | 0 | 0 | 0 | 2 | 6 | 8 | 16 | 15 | 6 | 0 | 0 | 0 | 53 |
| 1974 | 0 | 0 | 1 | 0 | 2 | 11 | 18 | 9 | 4 | 2 | 0 | 0 | 47 |
| 1975 | 1 | 0 | 0 | 0 | 4 | 10 | 14 | 11 | 4 | 1 | 0 | 0 | 45 |
| 1976 | 0 | 0 | 0 | 2 | 9 | 10 | 12 | 14 | 7 | 0 | 0 | 0 | 54 |
| 1977 | 0 | 0 | 0 | 6 | 10 | 11 | 19 | 12 | 3 | 0 | 0 | 0 | 61 |
| 1978 | 0 | 0 | 1 | 2 | 8 | 6 | 9 | 7 | 2 | 0 | 0 | 0 | 35 |
| 1979 | 0 | 0 | 0 | 0 | 5 | 6 | 16 | 12 | 4 | 0 | 0 | 0 | 43 |
| 1980 | 0 | 0 | 1 | 2 | 9 | 5 | 17 | 7 | 1 | 0 | 0 | 0 | 42 |
| 1981 | 0 | 0 | 0 | 0 | 12 | 11 | 13 | 17 | 9 | 0 | 0 | 0 | 62 |
| 1982 | 0 | 0 | 1 | 1 | 12 | 13 | 13 | 16 | 7 | 2 | 1 | 0 | 66 |
| 1983 | 0 | 1 | 2 | 0 | 5 | 16 | 18 | 13 | 5 | 1 | 1 | 0 | 62 |
| 1990 | 0 | 0 | 1 | 3 | 6 | 7 | 18 | 15 | 11 | 0 | 0 | 0 | 61 |
| 1991 | 0 | 0 | 1 | 1 | 14 | 17 | 17 | 16 | 6 | 0 | 0 | 0 | 72 |
| 1992 | 0 | 0 | 2 | 1 | 9 | 12 | 18 | 16 | 2 | 1 | 0 | 0 | 61 |
| 1993 | 0 | 0 | 0 | 2 | 14 | 8 | 9 | 13 | 6 | 0 | 0 | 0 | 52 |
| 1994 | 0 | 0 | 0 | 4 | 9 | 9 | 13 | 15 | 7 | 2 | 1 | 0 | 60 |
| 1995 | 0 | 0 | 0 | 2 | 13 | 14 | 8 | 11 | 10 | 0 | 0 | 0 | 58 |
| 1996 | 0 | 0 | 0 | 0 | 3 | 15 | 11 | 14 | 11 | 1 | 0 | 0 | 55 |
| 1997 | 0 | 0 | 0 | 0 | 8 | 19 | 13 | 21 | 4 | 1 | 0 | 0 | 66 |
| 1998 | 0 | 0 | 2 | 1 | 7 | 10 | 12 | 14 | 7 | 1 | 0 | 0 | 54 |
| 1999 | 0 | 0 | 0 | 0 | 9 | 9 | 13 | 14 | 4 | 0 | 0 | 0 | 49 |
| 2000 | 0 | 0 | 0 | 3 | 3 | 3 | 9 | 17 | 4 | 1 | 0 | 0 | 40 |
| 2001 | 0 | 0 | 2 | 3 | 5 | 7 | 18 | 15 | 8 | 1 | 0 | 0 | 59 |
| 2002 | 0 | 0 | 0 | 0 | 5 | 10 | 3 | 12 | 6 | 1 | 0 | 0 | 37 |
| 2003 | 0 | 0 | 0 | 10 | 10 | 13 | 11 | 6 | 2 | 0 | 0 | 0 | 52 |
| 2004 | 0 | 0 | 1 | 2 | 6 | 14 | 17 | 12 | 9 | 2 | 0 | 0 | 63 |
| 2005 | 0 | 0 | 0 | 2 | 6 | 15 | 11 | 9 | 5 | 1 | 0 | 0 | 49 |
| 2006 | 0 | 0 | 0 | 0 | 7 | 8 | 15 | 12 | 4 | 0 | 0 | 0 | 46 |
| 2007 | 0 | 0 | 1 | 1 | 1 | 14 | 8 | 11 | 15 | 6 | 2 | 0 | 59 |
| 2008 | 0 | 0 | 0 | 0 | 3 | 5 | 5 | 11 | 4 | 2 | 0 | 0 | 30 |
| 2009 | 0 | 0 | 0 | 1 | 6 | 17 | 15 | 10 | 6 | 0 | 0 | 0 | 55 |
| 2010 | 0 | 0 | 0 | 2 | 4 | 9 | 10 | 10 | 1 | 1 | 0 | 0 | 37 |
| 2011 | 0 | 0 | 0 | 3 | 3 | 8 | 20 | 7 | 2 | 1 | 1 | 1 | 49 |
| 2012 | 0 | 0 | 0 | 4 | 3 | 11 | 16 | 4 | 4 | 0 | 0 | 0 | 42 |
| 2013 | 0 | 0 | 1 | 0 | 4 | 10 | 15 | 16 | 7 | 2 | 0 | 0 | 63 |
| 2014 | 0 | 0 | 0 | 1 | 10 | 11 | 12 | 11 | 3 | 1 | 1 | 0 | 23 |
| 2015 | 0 | 0 | 0 | 2 | 13 | 16 | 11 | 8 | 3 | 3 | 0 | 0 | 42 |
| 2016 | 0 | 0 | 1 | 2 | 7 | 11 | 10 | 8 | 0 | 3 | 1 | 0 | 40 |
| 2017 | 0 | 0 | 0 | 2 | 7 | 8 | 7 | 12 | 4 | 1 | 0 | 0 | 33 |
| 2018 | 0 | 0 | 2 | 1 | 9 | 5 | 11 | 4 | 4 | 1 | 0 | 0 | 31 |
| 2019 | 0 | 0 | 0 | 2 | 7 | 17 | 15 | 6 | 5 | 0 | 0 | 0 | 41 |
| 2020 | 0 | 0 | 0 | 0 | 6 | 11 | 8 | 10 | 1 | 0 | 0 | 0 | 36 |
| 2021 | 0 | 0 | 0 | 2 | 9 | 7 | 12 | 9 | 5 | 1 | 0 | 0 | 44 |
| 2022 | 0 | 0 | 0 | 0 | 2 | 9 | 19 | 9 | 3 | 3 | 0 | 0 | 45 |
| 2023 | 0 | 0 | 0 | 1 | 12 | 15 | 18 | 8 | 5 | 2 | 0 | 0 | 61 |
| 2024 | 0 | 0 | 1 | 4 | 7 | 10 | 10 | 14 | 4 | 1 | 0 | 0 | 51 |
| 2025 | 0 | 0 | 2 | 2 | 8 | 12 | 15 | 12 | 7 | 0 | 58 |
Climatologies
| Years | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1991-2020 average | 0.0 | 0.0 | 0.4 | 1.7 | 7.0 | 11.2 | 12.0 | 11.5 | 5.2 | 1.0 | 0.2 | 0.03 |
| 1991-2020 std | 0.0 | 0.0 | 0.7 | 2.0 | 3.5 | 4.0 | 4.0 | 4.0 | 3.1 | 1.2 | 0.5 | 0.09 |
| 1981-2010 average | 0.00 | 0.04 | 0.54 | 1.63 | 7.40 | 11.46 | 12.42 | 13.3 | 6.37 | 1.00 | 0.21 | 0.00 |
| 1981-2010 std | 0.00 | 0.20 | 0.78 | 2.14 | 3.68 | 4.11 | 4.17 | 3.19 | 3.28 | 1.29 | .51 | 0.00 |
| 1971-1996 average | 0.10 | 0.10 | 0.50 | 1.60 | 8.20 | 11.10 | 14.30 | 12.60 | 5.80 | 0.70 | 0.20 | 0.00 |
| 1971-1996 std | 0.20 | 0.20 | 0.70 | 1.60 | 3.50 | 3.80 | 3.30 | 3.20 | 2.80 | 0.90 | .40 | 0.00 |
Thunderstorm data for 1971-present excludes the years 1984-1989 (not available).
Data was taken by a different person for the time periods 1971-1983 and 1990-present.
Days are 5pm MST to 5pm MST for 1990 to present and midnight-midnight for 1971-1983.