Lake Ōnoke – current water temperature and swimming conditions

This page provides information about the current water temperature at Lake Ōnoke in Wellington Region. Here you can view recent temperature trends on a 30-day chart, check typical monthly water temperature ranges, and compare today’s reading with historical averages for this date. A 7-day water temperature forecast, local weather conditions, and an overview of swimming suitability are also included.

Current Water Temperature

14.9°C

Today

16.0°C

Yesterday

16.3°C

A Week Ago

The water temperature in Lake Ōnoke today is 15°C.

Water Temperature in Lake Ōnoke: Daily Trends, Historical Records, and Forecast

⚠️ Lake temperatures between 10 and 15°C are cold but can be manageable for short swims on sunny, warm days. Shallow areas may feel slightly warmer, while deeper sections remain cold and slow to warm up. Most swimmers keep sessions brief, and wetsuits are often used for comfort. Wind and cooler air temperatures can quickly reduce how pleasant the swim feels.

Water Temperature Over the Last 30 Days

Water temperatures in Lake Ōnoke have been gradually cooling over the past month, with a further drop recorded during the last week.

According to our forecast, the water temperature in Lake Ōnoke will be 12.1°C in the next 7 days. See the table below for daily data for the upcoming week.

Table of Daily Water Temperature Data

Date	Current	Average	Forecast
May 6	15.4°C	11.7°C
May 7	15.4°C	11.7°C
May 8	16.3°C	11.7°C
May 9	16.3°C	11.7°C
May 10	16.4°C	11.7°C
May 11	16.4°C	11.7°C
May 12	16.0°C	11.7°C
May 13	16.0°C	11.7°C
May 14	14.9°C	11.7°C	14.9°C
May 15		11.7°C	14.5°C
May 16		11.7°C	14.1°C
May 17		11.7°C	13.7°C
May 18		11.7°C	13.3°C
May 19		11.7°C	12.9°C
May 20		11.7°C	12.5°C
May 21		11.7°C	12.1°C

* Current - Actual water temperature value

** Average - Average water temperature on this day in recent years

*** Forecast - Our water temperature forecast

Actual lake water temperatures may differ from the reported values by several degrees, particularly during periods of strong winds or rapid weather changes. Wind can mix surface and deeper layers in a lake, bringing cooler water to the surface, while shallow areas may warm more quickly under direct sunlight. Air temperature, sunshine, and cloud cover strongly influence how quickly a lake heats up or cools down. These factors can lead to noticeable temperature variations across different parts of the lake.

Our forecast is based on a proprietary mathematical model that considers real-time lake temperature observations, historical trends, seasonal cycles, wind strength and direction, and region-specific air temperature. To enhance accuracy, we also incorporate data from nearby monitored locations and comparable lakes within New Zealand.

Monthly Water Temperature Range (Min, Max & Average)

Month	Today	Yesterday	A Week Ago
January	11°C	17°C	22°C
February	12°C	17°C	22°C
March	10°C	16°C	21°C
April	8°C	12°C	16°C
May	7°C	11°C	15°C
June	5°C	10°C	14°C
July	4°C	8°C	11°C
August	5°C	9°C	12°C
September	5°C	10°C	14°C
October	6°C	13°C	19°C
November	6°C	12°C	18°C
December	9°C	14°C	19°C

Lake Ōnoke: Weather Forecast

May 15

10°C / 12°C

overcast

rain: 0% | wind: 16 km/h

May 16

10°C / 12°C

light drizzle

rain: 2% | wind: 15 km/h

May 17

7°C / 12°C

light drizzle

rain: 4% | wind: 17 km/h

May 18

6°C / 13°C

overcast

rain: 0% | wind: 14 km/h

May 19

7°C / 14°C

partly cloudy

rain: 3% | wind: 23 km/h

Location & Local Information

Lake Ōnoke, in the Wellington Region at the southern end of the Wairarapa, is a large coastal lagoon connected to Palliser Bay. It is shallow and strongly influenced by tides, wind and freshwater inflows from Lake Wairarapa. Water temperatures reflect seasonal air conditions and the mixing of fresh and salt water. In winter, surface temperatures are generally around 9–13°C. During spring, the lake gradually warms to approximately 13–17°C. In summer, particularly in January and February, shallow areas may reach about 18–23°C on warm, settled days, although tidal exchange can cause local variations. By autumn, temperatures usually ease back to between 13 and 17°C. Strong winds can quickly mix the water and affect comfort levels.

Swimming Conditions

Swimming is allowed at Lake Ōnoke, but it is not widely regarded as a prime swimming destination. While summer temperatures may feel comfortable when above 18°C, tidal currents near the outlet and variable water clarity require caution. The lake is more commonly used for boating, fishing and birdwatching. Anyone considering swimming should choose calm days, avoid the tidal channel and check local conditions beforehand. For most visitors, Lake Ōnoke is appreciated for its coastal scenery rather than recreational swimming.

Nearby Lakes

Frequently Asked Questions

What is the current water temperature in Lake Ōnoke?

The water temperature in Lake Ōnoke today is 15°C.

What is the water temperature in Lake Ōnoke during the summer months?

In summer, water temperatures in Lake Ōnoke at Wangi Wangi typically range from 9°C to 22°C.

Is it possible to swim in Lake Ōnoke (Wellington Region)?

Yes — people do swim, wade and paddle in Lake Ōnoke in fine weather, but it’s a shallow, brackish and often cold coastal lake with variable conditions, so it rarely feels like a typical summer swimming spot. Avoid the outlet and sandbar where strong currents and sudden breaches can occur, check local water‑quality advisories (e.g. LAWA) and on‑site signage before entering, and never swim alone.