A special weather statement continues for Niagara.
Environment Canada says rainfall amounts of 15 to 25 mm are likely tonight.
Although some spotty showers are occurring today, a more significant area of showers with embedded thunderstorms is expected to move into the region tonight.
Local rainfall amounts are forecast to be in the 15 to 25 mm range, but higher amounts are possible.
Some additional rainfall is also possible on Wednesday.
Heavy downpours can cause localized flooding in low-lying areas, and water pooling on roads. Higher water levels with increased flow in creeks and rivers are also possible.