Canada · 1991–2020

Best time to visit
Nepean

For Nepean, August has the most comfortable weather in our climate comparison. Typical daytime highs are 25.6°C, nights average 14.4°C, and rainfall totals about 78 mm. Figures use measured 1991–2020 normals from the nearest eligible NOAA station.

Best all-round monthAugust

Typical daytime high25.6°C

Typical night-time low14.4°C

August rainfall78 mm

Overall comfort

August

Other strong months: June and July

83/100 weather score

Outdoor sightseeing

September

Other strong months: May and August

80/100 weather score

Make the answer personal

Choose the weather
that suits you.

Set the daytime temperature and rainfall you are comfortable with. We will show only the months that meet every choice, using the measured 1991–2020 averages below.

Daytime high: at least 18°CDaytime high: at most 28°CMonthly rain: no more than 100 mmWet days: no more than 10

3 months fit your choices for Nepean

May19.2°C day · 76 mm rain · 9.9 wet days

August25.6°C day · 78 mm rain · 8.4 wet days

September20.8°C day · 90 mm rain · 9.8 wet days

The lowest comfort score is 5 out of 100. January, February, March, November and December share that score. In January, that is mainly because days reach only -6°C, 30° below the 24°C the score treats as ideal.

Quick answers

Planning a trip to Nepean?

These answers come from the same measured monthly climate record shown on this page.

When is the best time to visit Nepean?

August is the strongest all-round choice in our temperature-and-rainfall comparison, with a typical daytime high of 25.6°C and 78 mm of rain.

What is the hottest month in Nepean?

July is hottest in this record, with a typical daytime high of 26.4°C and a night-time low of 15.5°C.

Which month has the least rain?

February has the lowest monthly rainfall total at 50 mm.

Is this a weather forecast?

No. These are long-term measured averages from 1991–2020. Check a current forecast before you travel.

Month by month

See how the weather
changes through the year.

The bars combine daytime temperature, night-time temperature and rainfall. The figures are measured historical averages, not a forecast for a particular trip.

5-6° / -14.6°

5-3.6° / -13.1°

52.6° / -6.9°

2111.6° / 0.9°

5919.2° / 7.6°

8024.4° / 13.2°

7626.4° / 15.5°

8325.6° / 14.4°

6620.8° / 9.8°

2912.9° / 3.5°

55.8° / -2.1°

5-2° / -9.6°

Monthly climate evidence for Nepean — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-6°C	-14.6°C	66 mm	10.7	9 h 05	5	Good coverage
February	-3.6°C	-13.1°C	50 mm	8.8	10 h 19	5	Good coverage
March	2.6°C	-6.9°C	68 mm	9	11 h 46	5	Good coverage
April	11.6°C	0.9°C	80 mm	9.7	13 h 26	21	Good coverage
May	19.2°C	7.6°C	76 mm	9.9	14 h 51	59	Good coverage
June	24.4°C	13.2°C	98 mm	10.3	15 h 38	80	Good coverage
July	26.4°C	15.5°C	96 mm	10.2	15 h 20	76	Good coverage
August	25.6°C	14.4°C	78 mm	8.4	14 h 06	83	Good coverage
September	20.8°C	9.8°C	90 mm	9.8	12 h 28	66	Good coverage
October	12.9°C	3.5°C	85 mm	10.4	10 h 52	29	Good coverage
November	5.8°C	-2.1°C	78 mm	9.8	9 h 27	5	Good coverage
December	-2°C	-9.6°C	74 mm	11.4	8 h 45	5	Good coverage

Records at OTTAWA MACDONALD-CARTIER INT'L, 1938–2011
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	12.9°C13 Jan 2005	-35.6°C15 Jan 1957	44 mm25 Jan 2010	146 mm1995 · driest 15 mm in 1961	73
February	12.4°C27 Feb 2000	-36.1°C15 Feb 1943	40 mm21 Feb 1997	168 mm1971 · driest 2 mm in 1978	73
March	26.7°C29 Mar 1946	-30.6°C3 Mar 1950	44 mm21 Mar 1980	138 mm1947 · driest 13 mm in 1957	73
April	31.1°C27 Apr 1990	-16.7°C4 Apr 1954	46 mm2 Apr 2005	167 mm2011 · driest 14 mm in 2001	73
May	35.8°C26 May 2010	-5.6°C7 May 1966	48 mm31 May 2008	164 mm1986 · driest 24 mm in 1944	73
June	36.1°C27 Jun 1941	-0.1°C9 Jun 1980	90 mm24 Jun 2011	225 mm2002 · driest 14 mm in 1991	73
July	36.7°C1 Jul 1963	5.0°C15 Jul 1946	70 mm9 Jul 1967	244 mm2009 · driest 28 mm in 1976	73
August	37.8°C14 Aug 1944	2.6°C29 Aug 1986	67 mm10 Aug 2004	186 mm1952 · driest 8 mm in 1957	73
September	35.1°C9 Sep 2002	-3.0°C29 Sep 1980	135 mm9 Sep 2004	173 mm1945 · driest 13 mm in 1948	73
October	27.8°C7 Oct 1946	-7.8°C20 Oct 1946	76 mm6 Oct 1995	189 mm1995 · driest 7 mm in 1947	73
November	23.9°C6 Nov 1938	-21.7°C29 Nov 1940	46 mm26 Nov 2000	166 mm1963 · driest 27 mm in 1939	74
December	16.3°C3 Dec 1982	-34.4°C20 Dec 1942	44 mm9 Dec 1973	144 mm1983 · driest 19 mm in 2002	73

Typical days per month at OTTAWA MACDONALD-CARTIER INT'L, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	30	2	16
February	0	0	27	1	13
March	0	0	27	2	9
April	<1	<1	12	3	3
May	5	<1	<1	3	<1
June	15	3	0	3	0
July	21	5	0	3	0
August	18	4	0	3	0
September	6	1	<1	3	0
October	<1	0	7	3	<1
November	0	0	20	2	6
December	0	0	29	2	14

How often different weather occurs at OTTAWA MACDONALD-CARTIER INT'L, based on its daily record
Month	Dry days reaching 20°C	Wet days	Days with heavy rain	Weeks with 3+ wet days	Typical high by year
January	0%	36%	5%	48%	-9.8–-2.7°C
February	0%	33%	5%	43%	-7.1–-1.9°C
March	<1%	31%	7%	41%	-1.2–5.2°C
April	8%	31%	8%	37%	8.1–13.7°C
May	31%	32%	8%	40%	16.0–21.4°C
June	59%	31%	9%	40%	22.2–26.1°C
July	69%	30%	9%	36%	25.0–28.1°C
August	67%	27%	9%	29%	23.4–27.1°C
September	37%	30%	9%	38%	18.1–22.5°C
October	10%	31%	8%	39%	11.0–15.1°C
November	<1%	37%	8%	50%	2.7–7.9°C
December	0%	40%	8%	60%	-6.3–-0.1°C

A dry day reaching 20°C records under 1 mm of rain. A wet day records at least 1 mm, while a heavy-rain day records at least 10 mm. The weekly figure is the share of seven-day periods containing three or more wet days. The final column shows the middle 80% of average daytime highs recorded for that month in individual years; a wider range means conditions have varied more from one year to another.

1939Each stripe is one year’s mean temperature against the 72-year average. Warmest: 1998. Coolest: 1940.2010

The evidence behind this page

Where these figures
come from.

Place identity: GeoNames 6087029
NOAA station: CA006106000 · OTTAWA MACDONALD-CARTIER INT'L
Station distance: 4.9 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 20 usable years
Daylight: Calculated from latitude 45.34°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

Next step

Choose your month.
Then plan the details.

The weather comparison for Nepean is based on climate evidence, not payments from travel companies. Flight, accommodation and activity links will be clearly labelled when they are added; there are no booking offers on this page today.

How travel partnerships will work

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