New Zealand is forecast to shrug off the rainy start to summer with temperatures soaring into the 30s in some parts of the country in the coming week.

MetService forecaster Surprise Mhnongo told the Herald temperatures could reach the high 20s or early 30s in most places by Tuesday, especially the eastern parts of the North and South Islands.

“We’re expecting those temperatures to persist until the end of the week,” he said.

Mhnongo said Auckland could reach 25C by tomorrow and Tuesday, and slowly slide down to 22C by Friday.

According to MetService, Gisborne is set to reach a scorching 32C on Wednesday while temperatures could reach as high as 29C in Napier and Gisborne on Tuesday and Wednesday.

In the South Island, Alexandra, Banks Peninsula and Cromwell are all forecast to reach 28C on Tuesday and Wednesday and Blenheim is forecast to reach a high of 29C on Wednesday. Christchurch is also forecast to hit 27C on Tuesday and Wednesday.

“After that, there will be a bit of cooling. Not as major, but there will be a bit of cooling,” Mhnogo said.

Niwa estimated from around New Year La Nina-like conditions would bring more muggy and rainy conditions to places like Auckland and the Coromandel.

But unfortunately, despite the warm forecast ahead, dozens of Auckland’s most popular beaches were labelled unsafe to swim due to faecal contamination during the first weekend of summer.

Water quality website Safe Swim yesterday red-flagged 30 Waitematā Harbour beaches, meaning swimming is not advised, and black-flagged a further four inner harbour beaches warning not to swim there at all.

From Ōrewa to Takapuna Beach on Auckland’s North Shore, Safeswim labelled all but three beaches as unsafe, including the popular Long Bay, Browns Bay, Mairangi Bay, Milford Beach and Takapuna Beach.

Safeswim water quality models predict that levels of Faecal Indicator Bacteria breach national guidelines for swimming.

It advises people against swimming in contaminated water.