Weather on September 18
Round Rock, TX
55 Years of Data
Avg High
91°F
Avg Low
68°F
Warmest
1972
86°F avg
Coldest
1981
61°F avg
About This Date
September 18th in Round Rock, TX typically brings hot fall weather, with average highs around 91°F and lows near 68°F. Over 30 years of records, the warmest September 18th was in 1972 (86°F average), while the coldest was 1981 (61°F) — a 25°F range across recorded history. Rain or other precipitation has occurred on about 20% of September 18th dates historically, with the wettest September 18th recording 3.05" of rain.
Planning for September 18th in Round Rock, TX? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.3°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 96° | 69° | 83° | — | — |
| 2024 | 97° | 71° | 84° | — | — |
| 2023 | 91° | 65° | 78° | — | — |
| 2022 | 95° | 74° | 84° | — | — |
| 2021 | 94° | 68° | 81° | — | — |
| 2020 | 87° | 69° | 78° | — | — |
| 2019 | 88° | 70° | 79° | — | — |
| 2018 | 90° | 68° | 79° | — | — |
| 2017 | 91° | 72° | 81° | — | — |
| 2016 | 94° | 71° | 82° | — | — |
| 2015 | 93° | 74° | 83° | — | — |
| 2014 | 89° | 71° | 80° | 3.05" | — |
| 2013 | 94° | 70° | 82° | 0.03" | — |
| 2012 | 82° | 63° | 72° | — | — |
| 2011 | 92° | 70° | 81° | — | — |
| 2010 | 92° | 71° | 81° | 1.32" | — |
| 2009 | 81° | 66° | 73° | — | — |
| 2008 | 79° | 62° | 70° | 0.05" | — |
| 1982 | 99° | 68° | 83° | — | — |
| 1981coldest | 76° | 47° | 61° | — | — |
| 1980 | 98° | 68° | 83° | — | — |
| 1979 | 79° | 57° | 68° | 1.98" | — |
| 1978 | 94° | 70° | 82° | — | — |
| 1977 | 98° | 73° | 86° | — | — |
| 1976 | 92° | 70° | 81° | — | — |
| 1975 | 95° | 73° | 84° | — | — |
| 1974 | 87° | 70° | 78° | 0.08" | — |
| 1973 | 89° | 59° | 74° | — | — |
| 1972warmest | 96° | 75° | 86° | — | — |
| 1971 | 90° | 64° | 77° | — | — |
30 years of data from GEORGETOWN