unpredictable

/ʌnpɹɪdˈɪktəbə‍l/

/ˌənpɹɪˈdɪktəbəɫ/

unpredictable

unable to be predicted because of changing many times

unknown in advance

not occurring at a regular rate or fixed intervals

synonyms : irregular

Examples

1. The weather in April can be unpredictable, with both rain and sunshine.

2. Unpredictable tax systems that make things difficult for small enterprises and that prevent new investment.

3. The British weather is known for being unpredictable, with frequent rain showers.

4. They've never known the weather to be so unpredictable this time of year, it's been raining on and off for weeks.