Local temperature forecast performance

How accurate are temperature forecasts in Charleston, South Carolina?

In Charleston, next-day high and low temperature forecasts performed similarly: the typical miss was 2.1°F for highs and 2.1°F for lows.

See the current Charleston forecast

Opens ZIP 29401 using the nearest current station, which may differ from the archive station below.

What stands out

Charleston forecast findings

At a glance

Forecast day 1 accuracy

Highs Lows

Lower error than the national average

Charleston: 2.8°F typical miss National archive average: 3.5°F

Combined high and low results across forecast days 1, 3, 5, and 7.
High temperaturesForecast day 1
2.1°Ftypical miss

81% came within 3°F

Usually coolerUsually warmerLittle warm or cool tendency
Low temperaturesForecast day 1
2.1°Ftypical miss

79% came within 3°F

Usually coolerUsually warmer0.2°F warmer than observed

Error generally grows farther into the forecast

The dots show the typical miss on each forecast day.

Charleston temperature forecast error by forecast dayTypical miss by forecast day. day 1: high 2.1°F, low 2.1°F; day 3: high 2.6°F, low 2.3°F; day 5: high 3.2°F, low 2.9°F; day 7: high 3.8°F, low 3.7°F. typical miss ≤3°F 0°2°4°6°8°2.1°F2.1°FDay 12.6°F2.3°FDay 33.2°F2.9°FDay 53.8°F3.7°FDay 7
See within-3°F percentages and window timing
Day 1High: 81%Low: 79%
Day 3High: 71%Low: 73%
Day 5High: 64%Low: 64%
Day 7High: 56%Low: 55%

High and low windows represent the same numbered forecast day, but the high window ends 12 hours later and therefore has 12 more hours of lead time.

How forecasts change through the year

Each tile is forecast day 1’s typical miss.

Under 2°F2–3°F3–5°FOver 5°FNot enough data

High temperatures

Jan3.1°62 cases
Feb3.1°55 cases
Mar1.9°60 cases
Apr1.8°60 cases
May1.9°60 cases
Jun1.6°60 cases
Jul1.4°60 cases
Aug2.2°60 cases
Sep1.4°60 cases
Oct2.3°61 cases
Nov2.2°52 cases
Dec2.6°57 cases

Low temperatures

Jan2.8°62 cases
Feb2.1°55 cases
Mar2.2°60 cases
Apr2.8°59 cases
May1.9°60 cases
Jun1.9°60 cases
Jul1.6°59 cases
Aug1.5°61 cases
Sep1.4°60 cases
Oct2.1°61 cases
Nov2.0°52 cases
Dec2.6°57 cases
Data locationCharleston (CHS)10.2 miles from central Charleston · Archive 2024-08-01–2026-07-28

Based on archived raw NBM forecasts compared with observed daily highs and lows near Charleston. Results describe this model archive, not every forecast provider.

How these numbers are calculated

The forecasts are raw NBM median temperature guidance initialized at 12Z. Results include multiple NBM model eras and are retrospective, so they describe this archive rather than guaranteeing future performance.

“Typical miss” is mean absolute error: the average size of the error regardless of direction. Warmer or cooler tendency is signed bias, which can be small even when individual errors are larger.

Read the complete calibration and verification methodology.