If you haven't noticed the arctic chill blustering up the country, there's plenty more opportunity to get a cold blast of it, because winter is officially here to stay.
From the depths of the southern ocean a freezing breeze saw Aucklanders wake to temperatures as low as 3 degrees this morning, while parts of the central North Island, Tasman, the West Coast of the South Island and Central Otago also woke to a crisp frost on the ground.
And according to the Met Service, while you may be looking out at blue skies on your lunch break, some parts of the country face a low of 0C today.
So how can you stay warm tonight and throughout what may be a particularly chilly season?
EECA Energywise technical expert Christian Hoerning has provided some top tips to keep warm this winter:
Insulation is a life saver - literally
Well installed insulation that helps keep the heat in during winter is the priority. Insulation makes your house easier to heat properly, and more comfortable and healthy to live in. Colder houses place greater stress on older people, babies and the sick and are more likely to have mould that causes respiratory symptoms.
Insulation works by slowing heat loss from your house, making it easier to warm. If your house is not insulated, good quality, well-installed underfloor and ceiling insulation could halve your house's heat loss.
If you have insulation, it's worth checking to see if it is up to scratch. Old insulation may have settled, become damp or have gaps and no longer perform well. Sometimes insulation also gets moved around when people are doing work in the roof space or under the house.
Government programme Warmer Kiwi Homes offers grants from July 1 covering two thirds of the cost of ceiling and underfloor insulation, as well as ground vapour barriers.
Additional contributions from community organisations will be sought to make the retrofits as low cost as possible.
Grants covering two thirds of the cost of heating appliances will be available from July 2019.
Find the right heater for you
For larger rooms you want to heat regularly like a living room, it's worth paying a bit more upfront for a fixed heater with lower running costs and more heat output than an electric heater.
This could be a modern wood or wood-pellet burner, an energy-efficient heat pump, or a four-star flued gas heater.
Electric heaters may be enough for smaller rooms and rooms you only heat occasionally, like bedrooms - they're cheap to buy but more expensive to run.
Trap heat with quality curtains
Lined floor-length curtains can reduce window heat loss significantly. To work effectively, the curtains need to create a reasonably good seal to trap the air in the gap between the curtain and the window – if they are installed with gaps around their edges, air can circulate freely and won't insulate much.
There are curtain banks in many areas that offer free curtains to lower-income households.
Find a balanace with ventilation
Ventilation is important, but getting it right is a balancing act: if there is not enough ventilation, air quality won't be maintained and moist air will not be able to escape.
However, too much ventilation means a draughty, cold house.
Take control of excess moisture
Start with moisture hot spots: kitchens, laundries and bathrooms. Install extractor fans that vent outside (not into your roof cavity) to take away moist air.
If you can't install extractor fans, open the windows when you've been cooking, showering or drying clothes to let moisture escape that way.
Stop draughts in their tracks
Follow this up with some simple draught stopping. Fill any gaps in floorboards and around window and door frames.
Install weather stripping on the inside of window and door frames.
Fill your house with fresh air
Finally, make sure your house gets a regular airing – a quick blast of fresh air through the whole house a few times a day should be enough.
Home ventilation systems are a convenient alternative but can be expensive – just airing the house regularly yourself should achieve all the ventilation you need.
Low-cost tips for saving energy in winter
• Shut your curtains at dusk to keep the heat in.
• Use window insulation film. This is a cheap, easy way to insulate windows, although it's not as durable as actual double glazing. Used in conjunction with well-fitted, thermal backed curtains, it is a good, low-cost window insulation option.
• Only heat the room you're using. Keep the door closed and use door snakes to keep the heat in.
• If you have a heat pump, use its timer and thermostat and clean the filter regularly. No matter how great the specs, a heat pump cannot perform efficiently if you don't look after it or leave it on all the time at full bore.
• If you have a fireplace that isn't used, prevent draughts by filling a large plastic bag with crunched up newspaper (make sure people know they can't light the fire).
• Replace standard light bulbs with LED bulbs.
• Install a cylinder wrap around your electric hot water tank and insulate the first few metres of hot water pipe.
• Install an efficient shower head.
• Wash your clothes in cold water.