When travelling, we recommend packing in preparation to handle common weather conditions. The rainfall in Bangkok Intl is typically less than Hamilton, New Zealand. We can gather that this will continue over the next 3 days.
You can imagine temperatures to be in the 36 °C range in April. The weather in Hamilton, New Zealand is generally colder than Bangkok Intl's. As flight availability is subject to become more limited as peak season approaches it is ideal to book in a timely manner.