The yellow alert is in place in Zemgale and Latgale, and in Vidzeme the orange alert on rainfall and flooding has been announced.
In places already affected by flooding this month, residents should be prepared to protect themselves and their property.
Flooding of property and transport infrastructure, disruptions in electricity and water supply and telecommunications are likely. Driving conditions will potentially be dangerous due to reduced visibility and aquaplaning.
On Wednesday afternoon the sun will shine, according to forecasts.