I really like the idea of the sewers since there is now a sewing hut.

Since there's not likely to be anything to see with the children inside a building, not sure how that would add to gameplay.

As for the weather changes, I ran a 5-day forecast for two tropical islands in different parts of the world:

Barbados 5-Day Forecast (High/Low); Friday: Scattered Clouds, 82/78°F (27/25°C); Saturday: Scattered Clouds, 82/78°F (27/25°C); Sunday: Scattered Clouds, 82/78°F (27/25°C); Monday: Scattered Clouds, 82/78°F (27/25°C); Tuesday: Chance of Rain, 80/77°F (26/25°C)

Tahiti, French Polynesia 5-Day Forecast (High/Low); Friday: Chance of Rain, 87/77°F (30/25°C); Saturday: Chance of Rain, 89/75°F (31/23°C); Sunday: Rain, 84/80°F (28/26°C); Monday: Chance of Rain, 84/80°F (28/26°C); Tuesday: Rain, 86/82°F (30/27°C)

The only "weather change" would be substituting "scattered clouds" and hot/hotter for "chance of rain". A hurricane would be an event.