South Island New Zealand Weather in May

Average Temperatures in the South Island in May

In terms of the weather, you can look forward to a bit of everything on a South Island road trip during May. There’s plenty of sunny days between refreshing doses of rain, as well as both balmy late-summer temperatures and crisp, chilly nights announcing the arrival of the alpine winter snow and sport season. 

Here’s a closer look at what to expect, wherever you plan to go:

Christchurch:

May in Christchurch sees average daily highs of 14.7°C (58.5°F) and lows of 4.9°C, balancing out at average temperatures of 9.8°C for the whole month.

Dunedin

Dunedin doesn’t get as cold as its northern neighbours during May, with lengthy days still hanging around and allowing daily highs of 12.7°C (54.9°F), dropping to a mild 5.9°C low at night and overall 9.3°C average temperature.

Nelson and Marlborough:

The top of the South Island still turns it on in May. Nelson has average highs of 15.6°C (60.1°F), lows of 5.5°C and average temperatures of 10.5°C, while the average temperature for Blenheim in May is 10.2°C, with an average high of 16°C and low of 4.5°C.

Queenstown, Lake Tekapo and Mount Cook

Unsurprisingly, the Southern Alps and inland South Island lakes are where winter is felt earliest – but that can be a good thing: Queenstown has average daily temperatures of 7.0°C (44.6°F), highs of 11.7 and lows of 2.3°C, while the Lake Tekapo and Mount Cook region has an average daily temperature of 10.7°C, average highs of 5.9°C and average lows of 1.1°C. It is the season for gorgeous autumn colours, stunning starry skies, and the (potential) arrival of snow.

Average Sunshine Hours Per day in the South Island in May

Nelson and Marlborough:

There’s still plenty of long(-ish) nights and sunny days to enjoy in Nelson and Marlborough during May. Expect around 5.66 average sunshine hours per day in Nelson (175.7 total), and 5.57 in Blenheim (172.7 total). 

Christchurch

Christchurch has nice weather in May, with long pockets of sunshine intersected by occasional cloudy/overcast conditions. On average, you’ll get 4.69 average sunshine hours per day in Christchurch for May, totalling 140.8 for the month.

Dunedin 

Dunedin gets a total of 108.4 sunshine hours on average for May, equating to around 3.61 sunshine hours per day. 

Queenstown

Queenstown can get a real mixture of weather in May, and this can be seen in the average number of sunshine hours: 87.8 total for the month, with just under 3 hours (2.93) of sunshine per day.
 

Lake Tekapo & Mount Cook 

The mountainous geography of the central South Island can make for extremes in weather between close locations – and this is evident in the alpine High Country: Lake Tekapo, the centre of the South Island’s UNESCO-listed Dark Sky Reserve, gets nearly 5 hours (4.69) average sunshine hours a day in May (145.4 total), while Mount Cook – barely a half-hour drive away – is often shrouded in snowy cloud, with only 2.97 average sunshine hours per day (92.1 total).

Average rainfall in the South Island in May

The overall average rainfall across the South Island during May is relatively high compared with other months. It also comes along with, in some places, the arrival of the first snows of the season. 

There are plenty of dry spells between the showers, depending on where you plan to go:

As always, it’s wet on the West Coast in May, making it a great time to see the fabulous waterfalls of Milford Sound (596.6mm), while Hokitika (236.8mm) and Westport (174.2mm) get decent amounts of rain, too. Just over the ranges to the east, though, there’s a lot less rainfall in Nelson (82mm) and Blenheim (60.6mm), while Dunedin (64.7mm), Christchurch (63.7mm) and Queenstown (68.5mm) all see steady – but not extreme – average rainfall in May. Again, you can expect drastically different levels of rainfall between Lake Tekapo (56.5mm) and Mount Cook (357.1mm), despite being so close to each other.

Best things to do in the South Island in May 

See the Stars or Spot the Southern Lights

It’s always a great time to go stargazing beneath the Dark Sky Reserve in Lake Tekapo, but May is also a wonderful time of year to try and spot the stunning Aurora Australis, or “Southern Lights”, as nights begin to get longer. 

Enjoy Autumn in Central Otago

With wonderful autumnal colours, gorgeous 19th-century buildings and relatively warm temperatures, May is a wonderful time to visit Arrowtown and Central Otago before the snow arrives.

Explore the Marlborough Sounds and Abel Tasman National Park

May is a brilliant time of year to visit the top of the South Island, where sunny days and balmy temperatures tend to linger on longer than other regions. Explore the jaw-dropping Marlborough Sounds, discover Abel Tasman National Park, or visit Marlborough’s world-famous wineries as they’re busy winding up their harvest season.

Start planning a South Island holiday

If you like the sound of visiting the South Island in May, visit the First Light Travel website to help get you started. From exciting South Island self-drive itineraries to a New Zealand travel blog answering all your questions about visiting the South Island, you’ll find everything you need to know about planning your trip. If you want to organise your own customised itinerary, FLT’s travel experts – available to contact directly online – can help you do so.