Rain is vital for life. New Zealand’s mountainous terrain and location in the roaring forties mean rainfall varies across the country. Changes in rainfall amount or timing can significantly affect agriculture, energy, recreation, and the environment.

Glacier volume is strongly influenced by climate factors, such as temperature and precipitation. Changes in glacier ice volumes give some indication of changing climate conditions in New Zealand. 

New Zealand’s indigenous and exotic forests absorb and store carbon from the atmosphere through photosynthesis. As forests grow, the carbon stored in them increases.

El Niño Southern Oscillation (ENSO) is the movement of warm equatorial water across the Pacific Ocean and the atmospheric response. It occurs every 2–7 years, typically lasting 6–18 months.

Steady wind can be an important resource, but strong gusts can damage property, topple trees, and disrupt transportation, communications, and electricity.

The numbers of frost and warm days we experience each year change in response to many climate factors, such as the warming pattern induced by El Niño. These numbers indicate the variations in our climate and are an important consideration in agriculture.

Greenhouse gas (GHG) emissions from human activities increase the concentration of these gases in the atmosphere. GHGs absorb heat radiating from Earth’s surface and warm the atmosphere.

Ozone-depleting substances (ODS) are chemicals that can destroy ozone in the ozone layer of Earth's stratosphere. The ozone layer absorbs most of the sun's harmful ultraviolet (UV) light.

Greenhouse gases in the atmosphere absorb heat radiating from Earth, warming the atmosphere. Monitoring greenhouse gas concentrations allows us to infer long-term impacts on ocean acidity, temperature, sea level, and glaciers. 

Growing degree days (GDD) is the measure of how much warmth is available for plant and insect growth during a growing season. GDD information helps horticulturists and farmers predict plant growth and stock development.

In New Zealand, extreme weather events can be dangerous and costly, both socially and monetarily. They can cause damage that affects productivity and leads to millions of dollars in insurance claims. 

The Interdecadal Pacific Oscillation (IPO) is a long-term oscillation of the Pacific Ocean. It lasts from 20 to 30 years, much longer than the El Niño Southern Oscillation.

Lightning is the discharge of electricity from thunderstorms. Ground strikes can cause significant damage to property and infrastructure, and injure or kill people and livestock. Lightning is often associated with other severe weather events.

Temperature change is influenced by changes in atmospheric composition that result from greenhouse gas emissions. It is also linked to atmospheric circulation changes (eg the El Niño Southern Oscillation).

Our greenhouse gas (GHG) emissions are small compared with those of other developed nations, but we have committed to being part of the global response to climate change. 

Bacteria and parasites like Campylobacter, Salmonella, and Cryptosporidium can contaminate our food and water, leading to serious illness. 

Influenza is a potentially life-threatening virus that spreads quickly from person to person. It is a significant public health issue in this country, with 10–20 percent of New Zealanders infected every year. 

Skin cancers such as melanoma are linked to exposure to ultraviolet light. New Zealand has one of the world’s highest rates of melanoma. 

The ocean waters surrounding New Zealand vary in temperature from north to south. They interact with heat and moisture in the atmosphere and affect our weather.

Stratospheric ozone absorbs ultraviolet (UV) rays from the sun and protects Earth from harmful levels of UV.  Exposure to UV radiation has been linked to skin cancer.

Ozone is a gas that protects Earth from the sun’s harmful ultraviolet (UV) light. The ozone hole is an area of reduced ozone in the upper atmosphere (the stratosphere). 

Intense rainfall can result in flash floods or land slips that damage homes and property, disrupt transportation, and endanger lives. It can also interfere with recreation and increase erosion. Changes to the frequency of intense rainfall events can alter biodiversity.

The climate can affect ski-field operations. Warm temperatures can result in less snow or shorter ski seasons. Extreme weather events such as storms can close fields. 

Soil moisture is important for plant growth. A lack of moisture content over a growing season is a good indicator of drought, which can have social, environmental, and economic impacts.

A consistent band of westerly wind flows across the Southern Hemisphere and circles the South Pole. The Southern Annular Mode (SAM) describes how this band moves, either north towards the equator or south towards Antarctica.

Sunshine is important for our health and recreation, and for the environment. It is also important for our agriculture-based economy, for example, for plant growth. 

We need sunlight to exist. However, too much exposure to the sun's ultraviolet (UV) light can cause skin cancer. Ozone in the upper atmosphere absorbs some of the sun’s UV light, protecting us from harmful levels.

Precipitation and evapotranspiration are important components of the water cycle. They influence the amount of water available for forests and crops and contribute to river, lake, and aquifer levels.