Climate and Average Weather Year Round in Hamilton New Zealand

In Hamilton, the summers are comfortable; the winters are cold, wet, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 42°F to 76°F and is rarely below 31°F or above 81°F.

Based on the tourism score, the best time of year to visit Hamilton for warm-weather activities is from early January to early March.

The warm season lasts for 3.1 months, from December 15 to March 19, with an average daily high temperature above 72°F. The hottest month of the year in Hamilton is February, with an average high of 76°F and low of 59°F.

The cool season lasts for 3.4 months, from May 25 to September 7, with an average daily high temperature below 60°F. The coldest month of the year in Hamilton is July, with an average low of 42°F and high of 57°F.

In Hamilton, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year in Hamilton begins around January 2 and lasts for 3.4 months, ending around April 15.

The clearest month of the year in Hamilton is March, during which on average the sky is clear, mostly clear, or partly cloudy 68% of the time.

The cloudier part of the year begins around April 15 and lasts for 8.6 months, ending around January 2.

The cloudiest month of the year in Hamilton is July, during which on average the sky is overcast or mostly cloudy 47% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Hamilton varies throughout the year.

The wetter season lasts 5.3 months, from May 7 to October 15, with a greater than 31% chance of a given day being a wet day. The month with the most wet days in Hamilton is July, with an average of 11.7 days with at least 0.04 inches of precipitation.

The drier season lasts 6.7 months, from October 15 to May 7. The month with the fewest wet days in Hamilton is February, with an average of 6.9 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Hamilton is July, with an average of 11.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 39% on July 7.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Hamilton experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Hamilton. The month with the most rain in Hamilton is July, with an average rainfall of 3.8 inches.

The month with the least rain in Hamilton is November, with an average rainfall of 2.3 inches.

The length of the day in Hamilton varies significantly over the course of the year. In 2024, the shortest day is June 21, with 9 hours, 33 minutes of daylight; the longest day is December 21, with 14 hours, 47 minutes of daylight.

The earliest sunrise is at 5:50 AM on December 7, and the latest sunrise is 1 hour, 47 minutes later at 7:37 AM on April 6. The earliest sunset is at 5:06 PM on June 13, and the latest sunset is 3 hours, 38 minutes later at 8:44 PM on January 5.

Daylight saving time (DST) is observed in Hamilton during 2024, starting in the spring on September 29 and ending in the fall on April 7.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Hamilton, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 4% of 4% throughout.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Hamilton experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 3.9 months, from August 19 to December 15, with average wind speeds of more than 10.5 miles per hour. The windiest month of the year in Hamilton is October, with an average hourly wind speed of 11.5 miles per hour.

The calmer time of year lasts for 8.1 months, from December 15 to August 19. The calmest month of the year in Hamilton is April, with an average hourly wind speed of 9.2 miles per hour.

The predominant average hourly wind direction in Hamilton is from the west throughout the year.

Hamilton is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.9 months, from January 5 to April 2, with an average temperature above 67°F. The month of the year in Hamilton with the warmest water is February, with an average temperature of 69°F.

The time of year with cooler water lasts for 3.9 months, from June 23 to October 19, with an average temperature below 59°F. The month of the year in Hamilton with the coolest water is August, with an average temperature of 57°F.

To characterize how pleasant the weather is in Hamilton throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Hamilton for general outdoor tourist activities is from early January to early March, with a peak score in the second week of February.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Hamilton for hot-weather activities is from mid January to mid February, with a peak score in the first week of February.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Hamilton typically lasts for 9.8 months (298 days), from around August 17 to around June 10, rarely starting after September 16, or ending before May 19.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Hamilton should appear around August 16, only rarely appearing before August 6 or after August 31.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.5 months, from November 2 to February 18, with an average daily incident shortwave energy per square meter above 6.4 kWh. The brightest month of the year in Hamilton is January, with an average of 7.4 kWh.

The darker period of the year lasts for 3.6 months, from April 30 to August 17, with an average daily incident shortwave energy per square meter below 3.0 kWh. The darkest month of the year in Hamilton is June, with an average of 1.9 kWh.

For the purposes of this report, the geographical coordinates of Hamilton are -37.783 deg latitude, 175.283 deg longitude, and 128 ft elevation.

The topography within 2 miles of Hamilton contains only modest variations in elevation, with a maximum elevation change of 180 feet and an average elevation above sea level of 140 feet. Within 10 miles contains only modest variations in elevation (551 feet). Within 50 miles contains significant variations in elevation (3,327 feet).

The area within 2 miles of Hamilton is covered by grassland (44%), artificial surfaces (39%), and trees (10%), within 10 miles by cropland (80%), and within 50 miles by cropland (36%) and trees (30%).