Quesnel
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Quesnel clear sky chart from 2005-11-06 to 2025-03-27.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	9% 10% 4 9% 6% 6% 6% 5% 6% 7% 32%	111804
	Night	10% 13% 4 10% 6% 6% 5% 4 6% 7% 28%	116167
Transparency	Day	48% 9% 15% 19% 7% 1	111543
	Night	53% 9% 14% 17% 6% 1	116074
Seeing	Day	15% 12% 25% 27% 17% 4	16614
	Night	18% 11% 21% 29% 18% 2	24799

By Month

Percentage Cloud Cover NW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	8% 17% 6% 15% 8% 8% 6% 5% 6% 5% 16%	3112
	11th to 20th	Day	10% 12% 4 10% 6% 5% 6% 5% 7% 6% 28%	3159
	21st to end	Day	10% 16% 5% 11% 6% 6% 4 4 6% 6% 25%	3558
February	1st to 10th	Day	13% 16% 5% 11% 7% 5% 5% 3 5% 6% 24%	1668
	11th to 20th	Day	9% 15% 6% 10% 6% 7% 5% 4 5% 6% 25%	1755
	21st to end	Day	6% 14% 6% 12% 8% 4 5% 4 6% 7% 28%	1485
March	1st to 10th	Day	4 12% 5% 10% 8% 6% 6% 5% 7% 9% 26%	3245
	11th to 20th	Day	5% 11% 3 11% 7% 7% 7% 5% 8% 9% 28%	3600
	21st to end	Day	6% 11% 4 9% 6% 6% 6% 5% 7% 7% 34%	4046
April	1st to 10th	Day	7% 13% 5% 10% 9% 8% 7% 5% 5% 6% 24%	2280
	11th to 20th	Day	8% 13% 3 10% 7% 6% 6% 5% 7% 7% 27%	2398
	21st to end	Day	10% 10% 4 10% 7% 7% 6% 5% 6% 8% 28%	2636
May	1st to 10th	Day	7% 9% 3 9% 6% 6% 5% 5% 7% 9% 35%	4420
	11th to 20th	Day	10% 8% 3 9% 7% 7% 7% 6% 7% 7% 28%	4468
	21st to end	Day	13% 11% 4 10% 6% 6% 8% 6% 7% 7% 23%	5309
June	1st to 10th	Day	12% 8% 3 9% 7% 6% 6% 5% 6% 8% 31%	3040
	11th to 20th	Day	13% 9% 3 9% 6% 7% 6% 6% 7% 8% 27%	3040
	21st to end	Day	9% 7% 3 9% 6% 6% 6% 5% 8% 9% 32%	3040
July	1st to 10th	Day	6% 5% 2 5% 4 4 4 4 6% 7% 53%	4973
	11th to 20th	Day	5% 4 1 4 3 3 3 4 6% 8% 57%	4740
	21st to end	Day	8% 6% 2 7% 5% 6% 7% 5% 8% 9% 36%	5138
August	1st to 10th	Day	3 3 2 4 3 3 4 4 5% 8% 61%	4415
	11th to 20th	Day	5% 5% 2 6% 4 5% 6% 4 7% 9% 47%	4238
	21st to end	Day	11% 8% 3 9% 6% 5% 6% 5% 6% 8% 34%	4477
September	1st to 10th	Day	11% 6% 2 7% 5% 5% 4 3 6% 8% 42%	2280
	11th to 20th	Day	11% 8% 3 6% 6% 5% 5% 4 5% 8% 39%	2280
	21st to end	Day	16% 10% 4 8% 6% 5% 5% 4 5% 7% 30%	2007
October	1st to 10th	Day	13% 14% 5% 11% 6% 6% 5% 5% 5% 6% 25%	3180
	11th to 20th	Day	17% 13% 4 9% 5% 4 5% 4 5% 7% 26%	3146
	21st to end	Day	11% 10% 4 11% 6% 6% 5% 4 6% 7% 30%	2913
November	1st to 10th	Day	17% 14% 4 9% 6% 5% 5% 5% 6% 5% 22%	1568
	11th to 20th	Day	12% 16% 6% 10% 9% 7% 5% 4 6% 6% 20%	1600
	21st to end	Day	12% 21% 5% 11% 9% 7% 5% 4 5% 6% 14%	1376
December	1st to 10th	Day	14% 19% 5% 14% 9% 6% 6% 4 6% 4 13%	1960
	11th to 20th	Day	10% 18% 7% 12% 9% 7% 7% 5% 6% 6% 12%	2262
	21st to end	Day	7% 19% 5% 13% 6% 6% 5% 4 5% 8% 22%	2992
January	1st to 10th	Night	9% 17% 6% 14% 7% 7% 6% 4 5% 5% 19%	6876
	11th to 20th	Night	9% 16% 6% 11% 6% 5% 5% 4 6% 6% 28%	6739
	21st to end	Night	11% 18% 5% 11% 6% 5% 5% 4 6% 6% 24%	7397
February	1st to 10th	Night	13% 16% 5% 11% 6% 6% 5% 4 5% 6% 22%	2730
	11th to 20th	Night	9% 15% 7% 11% 5% 5% 5% 4 6% 7% 27%	2532
	21st to end	Night	8% 16% 5% 10% 6% 4 6% 4 6% 6% 30%	2145
March	1st to 10th	Night	5% 15% 4 10% 6% 7% 7% 5% 7% 9% 26%	3845
	11th to 20th	Night	4 12% 4 11% 9% 8% 7% 6% 7% 7% 25%	3599
	21st to end	Night	7% 11% 4 7% 6% 6% 6% 5% 7% 7% 34%	3745
April	1st to 10th	Night	7% 13% 4 10% 7% 6% 6% 5% 6% 7% 28%	1900
	11th to 20th	Night	9% 10% 4 8% 6% 7% 6% 6% 8% 8% 26%	1729
	21st to end	Night	10% 11% 3 10% 6% 5% 6% 5% 7% 6% 32%	1543
May	1st to 10th	Night	11% 11% 3 9% 6% 5% 4 4 5% 6% 36%	2540
	11th to 20th	Night	15% 9% 3 9% 6% 6% 6% 4 6% 9% 27%	2422
	21st to end	Night	21% 11% 4 8% 7% 5% 4 4 5% 6% 25%	2264
June	1st to 10th	Night	14% 9% 3 7% 6% 5% 6% 6% 5% 6% 33%	1140
	11th to 20th	Night	17% 9% 3 10% 5% 6% 6% 5% 7% 9% 24%	1140
	21st to end	Night	13% 7% 4 8% 8% 6% 6% 5% 6% 9% 29%	1140
July	1st to 10th	Night	7% 4 1 4 4 4 4 5% 6% 6% 54%	1984
	11th to 20th	Night	6% 3 2 5% 4 3 3 4 6% 7% 57%	2220
	21st to end	Night	13% 6% 3 8% 6% 5% 5% 4 7% 9% 35%	2414
August	1st to 10th	Night	4 4 1 4 3 4 3 3 6% 7% 61%	2515
	11th to 20th	Night	6% 5% 2 6% 5% 5% 5% 4 7% 10% 44%	2589
	21st to end	Night	14% 8% 2 8% 5% 5% 5% 5% 8% 8% 32%	3178
September	1st to 10th	Night	11% 5% 2 7% 5% 5% 5% 4 6% 8% 41%	1900
	11th to 20th	Night	10% 6% 2 8% 6% 6% 5% 4 6% 6% 42%	1900
	21st to end	Night	15% 10% 4 8% 6% 5% 5% 4 6% 7% 32%	2171
October	1st to 10th	Night	14% 13% 4 11% 7% 5% 5% 4 6% 7% 24%	3800
	11th to 20th	Night	12% 10% 3 9% 6% 6% 6% 4 7% 10% 27%	3790
	21st to end	Night	11% 11% 4 11% 7% 6% 6% 4 5% 6% 29%	4638
November	1st to 10th	Night	17% 14% 4 10% 6% 6% 6% 4 6% 6% 21%	2730
	11th to 20th	Night	13% 14% 4 11% 7% 6% 6% 5% 6% 6% 22%	2800
	21st to end	Night	13% 18% 5% 12% 8% 6% 5% 5% 6% 6% 17%	2998
December	1st to 10th	Night	12% 16% 5% 11% 7% 6% 6% 5% 6% 6% 19%	5220
	11th to 20th	Night	13% 22% 7% 13% 8% 5% 5% 4 5% 5% 15%	5930
	21st to end	Night	7% 16% 7% 12% 7% 6% 6% 4 6% 6% 23%	7964

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	65% 13% 10% 9% 2	3112
	11th to 20th	Day	54% 7% 14% 16% 5% 4	3180
	21st to end	Day	59% 11% 17% 12% 2	3558
February	1st to 10th	Day	61% 6% 12% 10% 11% 1	1668
	11th to 20th	Day	59% 8% 16% 13% 4	1764
	21st to end	Day	55% 8% 14% 14% 8% 1	1485
March	1st to 10th	Day	50% 11% 11% 18% 10% 1	3245
	11th to 20th	Day	47% 12% 15% 22% 5%	3600
	21st to end	Day	46% 10% 14% 20% 10% 1	4046
April	1st to 10th	Day	57% 10% 13% 14% 6%	2280
	11th to 20th	Day	52% 9% 12% 19% 7% 1	2398
	21st to end	Day	52% 9% 13% 19% 7%	2636
May	1st to 10th	Day	42% 8% 16% 26% 6% 1	4420
	11th to 20th	Day	50% 10% 13% 19% 8% 1	4471
	21st to end	Day	53% 11% 15% 16% 4	5310
June	1st to 10th	Day	49% 10% 13% 17% 10% 1	3040
	11th to 20th	Day	51% 12% 14% 18% 5%	3040
	21st to end	Day	45% 11% 18% 20% 6% 1	3040
July	1st to 10th	Day	29% 8% 11% 26% 23% 4	4896
	11th to 20th	Day	24% 7% 18% 32% 16% 2	4659
	21st to end	Day	40% 9% 18% 21% 10% 2	4976
August	1st to 10th	Day	21% 7% 15% 40% 16% 1	4397
	11th to 20th	Day	32% 9% 22% 29% 9%	4280
	21st to end	Day	46% 9% 24% 18% 3	4476
September	1st to 10th	Day	40% 10% 22% 21% 7%	2280
	11th to 20th	Day	43% 10% 18% 21% 8%	2280
	21st to end	Day	52% 9% 17% 15% 5% 1	2007
October	1st to 10th	Day	57% 9% 18% 12% 4	3180
	11th to 20th	Day	57% 8% 20% 14% 2	3146
	21st to end	Day	52% 9% 22% 14% 3	2913
November	1st to 10th	Day	62% 9% 12% 13% 4	1568
	11th to 20th	Day	65% 10% 11% 10% 5%	1600
	21st to end	Day	69% 11% 8% 9% 3	1376
December	1st to 10th	Day	72% 11% 9% 6% 2	1960
	11th to 20th	Day	69% 10% 10% 6% 5%	2264
	21st to end	Day	60% 9% 15% 14% 3	2992
January	1st to 10th	Night	64% 8% 12% 12% 3	6876
	11th to 20th	Night	56% 6% 14% 11% 7% 5%	6780
	21st to end	Night	61% 9% 17% 11% 2	7397
February	1st to 10th	Night	63% 6% 10% 11% 9%	2730
	11th to 20th	Night	55% 8% 16% 15% 6% 1	2534
	21st to end	Night	52% 8% 14% 17% 7% 2	2145
March	1st to 10th	Night	49% 11% 12% 19% 9% 1	3845
	11th to 20th	Night	48% 12% 14% 19% 6% 1	3600
	21st to end	Night	43% 10% 13% 22% 12%	3745
April	1st to 10th	Night	52% 8% 13% 18% 9%	1900
	11th to 20th	Night	49% 10% 13% 20% 8%	1729
	21st to end	Night	50% 9% 10% 22% 9% 1	1543
May	1st to 10th	Night	46% 8% 13% 24% 8% 1	2540
	11th to 20th	Night	48% 10% 14% 22% 6%	2422
	21st to end	Night	58% 8% 11% 18% 4	2264
June	1st to 10th	Night	49% 11% 11% 18% 11% 1	1140
	11th to 20th	Night	54% 10% 14% 17% 5%	1140
	21st to end	Night	50% 12% 14% 17% 6% 1	1140
July	1st to 10th	Night	29% 9% 9% 26% 23% 5%	1952
	11th to 20th	Night	26% 6% 14% 39% 14% 1	2178
	21st to end	Night	43% 8% 18% 17% 13% 2	2337
August	1st to 10th	Night	23% 6% 13% 43% 15%	2508
	11th to 20th	Night	33% 9% 18% 31% 9% 1	2613
	21st to end	Night	46% 9% 25% 16% 3 1	3178
September	1st to 10th	Night	40% 10% 16% 25% 8% 1	1900
	11th to 20th	Night	40% 9% 13% 27% 9% 1	1900
	21st to end	Night	50% 8% 14% 18% 9%	2171
October	1st to 10th	Night	58% 8% 16% 14% 4	3800
	11th to 20th	Night	50% 9% 17% 22% 3	3790
	21st to end	Night	54% 8% 19% 14% 4	4638
November	1st to 10th	Night	63% 9% 11% 13% 5%	2730
	11th to 20th	Night	60% 10% 11% 13% 5%	2800
	21st to end	Night	66% 10% 10% 10% 4 1	2998
December	1st to 10th	Night	64% 10% 15% 8% 3	5220
	11th to 20th	Night	71% 9% 9% 7% 4	5927
	21st to end	Night	60% 8% 15% 12% 4	7964

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	19% 18% 24% 27% 8% 5%	200
	11th to 20th	Day	17% 18% 26% 25% 13% 2	200
	21st to end	Day	21% 22% 23% 22% 8% 4	220
February	1st to 10th	Day	23% 20% 24% 17% 14% 3	268
	11th to 20th	Day	16% 14% 33% 23% 12% 2	395
	21st to end	Day	15% 21% 34% 19% 9% 1	331
March	1st to 10th	Day	16% 18% 29% 22% 13% 2	496
	11th to 20th	Day	15% 21% 29% 21% 12% 2	500
	21st to end	Day	19% 17% 28% 20% 13% 4	531
April	1st to 10th	Day	17% 19% 29% 23% 10% 2	460
	11th to 20th	Day	13% 17% 30% 23% 11% 6%	452
	21st to end	Day	14% 17% 25% 26% 14% 5%	460
May	1st to 10th	Day	10% 14% 32% 26% 13% 4	463
	11th to 20th	Day	10% 9% 27% 28% 20% 5%	539
	21st to end	Day	12% 10% 24% 29% 21% 4	818
June	1st to 10th	Day	14% 10% 27% 29% 17% 3	870
	11th to 20th	Day	17% 9% 23% 27% 20% 4	870
	21st to end	Day	11% 8% 19% 33% 24% 5%	870
July	1st to 10th	Day	11% 4 20% 33% 26% 6%	810
	11th to 20th	Day	10% 9% 17% 33% 25% 6%	668
	21st to end	Day	7% 5% 20% 34% 26% 7%	739
August	1st to 10th	Day	6% 5% 18% 35% 27% 10%	501
	11th to 20th	Day	7% 7% 23% 30% 24% 9%	477
	21st to end	Day	11% 10% 26% 28% 20% 5%	539
September	1st to 10th	Day	15% 8% 22% 26% 20% 8%	490
	11th to 20th	Day	15% 9% 19% 29% 20% 8%	490
	21st to end	Day	23% 13% 28% 23% 11% 2	490
October	1st to 10th	Day	24% 13% 22% 21% 16% 4	490
	11th to 20th	Day	23% 14% 26% 20% 16% 1	487
	21st to end	Day	25% 15% 26% 24% 9% 3	270
November	1st to 10th	Day	32% 21% 25% 14% 7% 3	200
	11th to 20th	Day	23% 18% 25% 22% 9% 4	200
	21st to end	Day	22% 19% 26% 18% 10% 6%	200
December	1st to 10th	Day	23% 15% 21% 26% 12% 5%	200
	11th to 20th	Day	15% 15% 22% 30% 17% 3	200
	21st to end	Day	22% 15% 26% 24% 10% 4	220
January	1st to 10th	Night	22% 16% 26% 24% 11% 2	945
	11th to 20th	Night	23% 13% 25% 27% 12% 1	900
	21st to end	Night	21% 17% 22% 26% 12% 2	978
February	1st to 10th	Night	23% 14% 19% 26% 15% 3	800
	11th to 20th	Night	17% 13% 20% 35% 14% 2	784
	21st to end	Night	17% 12% 24% 31% 15% 2	660
March	1st to 10th	Night	15% 16% 23% 28% 15% 3	800
	11th to 20th	Night	12% 16% 28% 28% 14% 2	800
	21st to end	Night	15% 11% 20% 30% 23% 2	862
April	1st to 10th	Night	15% 10% 22% 31% 19% 4	760
	11th to 20th	Night	13% 9% 24% 34% 17% 2	601
	21st to end	Night	14% 11% 28% 28% 16% 2	403
May	1st to 10th	Night	15% 10% 22% 31% 19% 2	380
	11th to 20th	Night	12% 5% 20% 35% 25% 3	374
	21st to end	Night	15% 7% 20% 29% 26% 3	411
June	1st to 10th	Night	18% 7% 19% 35% 18% 2	380
	11th to 20th	Night	19% 7% 18% 31% 22% 3	380
	21st to end	Night	12% 6% 13% 39% 27% 3	380
July	1st to 10th	Night	12% 3 15% 34% 35% 2	370
	11th to 20th	Night	12% 4 18% 33% 31% 3	368
	21st to end	Night	10% 2 13% 37% 32% 6%	416
August	1st to 10th	Night	5% 4 11% 33% 40% 6%	378
	11th to 20th	Night	7% 2 12% 36% 37% 5%	429
	21st to end	Night	16% 5% 13% 35% 28% 4	646
September	1st to 10th	Night	14% 4 17% 38% 25% 3	760
	11th to 20th	Night	13% 6% 16% 31% 28% 7%	760
	21st to end	Night	22% 8% 25% 27% 16% 1	760
October	1st to 10th	Night	20% 9% 18% 33% 16% 3	760
	11th to 20th	Night	23% 12% 20% 25% 18% 2	760
	21st to end	Night	21% 14% 24% 26% 13% 2	836
November	1st to 10th	Night	27% 17% 20% 27% 8% 2	780
	11th to 20th	Night	24% 14% 28% 23% 11% 1	800
	21st to end	Night	27% 14% 23% 24% 10% 2	968
December	1st to 10th	Night	20% 12% 21% 30% 15% 2	1100
	11th to 20th	Night	23% 14% 22% 28% 12% 1	1100
	21st to end	Night	20% 16% 25% 27% 11% 2	1210

Page generated at 2025-03-24 06:04:26. Version ac07

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