The variability of precipitation generally increases inland across the state and away from the Gulf of Mexico. The state has two pronounced rainy seasons in the spring and fall. Both rainy seasons are impacted by polar fronts interacting with moist Gulf air during those seasons, with the fall rainy season also impacted by hurricanes and tropical depressions. Most of the annual rainfall in Louisiana occurs during rainstorms when a large amount of precipitation falls over a short period. The table below shows the variation in the monthly rainfall totals in inches across the state.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Alexandria | 5.44 | 5.34 | 5.30 | 4.55 | 4.72 | 5.38 | 4.39 | 4.11 | 3.93 | 5.27 | 6.19 | 6.24 | 60.86 |
| Lake Charles | 5.23 | 3.46 | 3.66 | 3.33 | 5.20 | 6.85 | 5.63 | 4.86 | 5.26 | 4.90 | 4.43 | 4.68 | 57.49 |
| New Orleans | 4.90 | 4.56 | 4.74 | 4.35 | 4.42 | 7.14 | 7.94 | 6.20 | 5.80 | 3.79 | 4.11 | 4.34 | 62.29 |
| Shreveport | 4.20 | 4.75 | 4.14 | 4.19 | 4.93 | 5.40 | 3.65 | 2.73 | 3.16 | 4.96 | 4.53 | 4.77 | 51.41 |