The Met Office put out the alert for rain across the east coast of Scotland. This means downpours could cause “disruption”, the weather service warned.
The warning is in place between Perth and Aberdeen from 9pm on Wednesday until 6am on Thursday.
The Met Office suggests that travellers could face longer journey times due to roads flooding, as well as public transport likely to see some delays.
They added that “flooding of a few homes and businesses is possible”.
Heading into Wednesday evening, “prolonged” showers are likely across Scotland and Northern Ireland.
Temperatures will peak at 16C in the north of Scotland on Thursday, accompanied by showers and a noticeable breeze.
In Edinburgh, temperatures will stretch up to 19C with a brighter, sunnier outlook to the “moderate breeze”, according to the BBC.
Sunny spells will break through the clouds for parts of Thursday across Northern Ireland, with temperatures touching 17C.
The outlook will be similar across the northwest of England and through to the northwest, will expect highs of 22C and outbursts of sun.
Temperatures in south Wales will comfortably surpass 20C, reaching 22C in Cardiff on Tuesday.
Temperatures will be highest in London, with a gentle breeze forecast alongside 25C in the capital.