Manning Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Manning Provincial Park clear sky chart from 2005-11-06 to 2025-10-19.

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	7% 15% 5% 11% 6% 5% 5% 3 5% 6% 32%	131054
	Night	6% 15% 6% 12% 7% 5% 5% 4 5% 6% 30%	127320
Transparency	Day	26% 42% 10% 12% 8% 2	130772
	Night	25% 43% 11% 12% 7% 1	127179
Seeing	Day	17% 22% 31% 21% 8% 2	16151
	Night	11% 15% 32% 28% 12% 1	24460

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	5% 25% 10% 15% 6% 5% 4 3 5% 6% 15%	3269
	11th to 20th	Day	2 12% 5% 13% 8% 7% 6% 5% 6% 7% 28%	3616
	21st to end	Day	5% 14% 5% 16% 8% 6% 5% 3 4 4 29%	4004
February	1st to 10th	Day	5% 22% 7% 17% 8% 6% 4 3 6% 6% 16%	1722
	11th to 20th	Day	5% 19% 8% 15% 7% 5% 5% 4 5% 5% 21%	1755
	21st to end	Day	4 24% 8% 14% 9% 6% 7% 4 4 3 15%	1595
March	1st to 10th	Day	2 17% 7% 16% 8% 7% 7% 5% 6% 6% 20%	4518
	11th to 20th	Day	2 20% 10% 17% 7% 5% 4 3 4 4 25%	4906
	21st to end	Day	6% 26% 8% 14% 7% 6% 5% 4 4 5% 14%	5810
April	1st to 10th	Day	8% 25% 8% 15% 7% 5% 5% 3 4 6% 13%	2400
	11th to 20th	Day	6% 21% 7% 12% 7% 5% 5% 4 5% 6% 22%	2372
	21st to end	Day	11% 23% 7% 11% 7% 5% 4 3 4 5% 19%	2733
May	1st to 10th	Day	8% 17% 4 10% 5% 5% 4 3 4 5% 36%	6320
	11th to 20th	Day	11% 25% 6% 11% 5% 4 4 3 4 7% 20%	6277
	21st to end	Day	14% 20% 5% 11% 5% 4 4 3 5% 6% 22%	6903
June	1st to 10th	Day	18% 15% 3 9% 6% 4 5% 4 4 7% 25%	2851
	11th to 20th	Day	20% 18% 4 10% 6% 5% 5% 4 5% 5% 20%	3000
	21st to end	Day	13% 11% 3 8% 5% 4 6% 4 5% 7% 34%	3000
July	1st to 10th	Day	5% 5% 2 5% 3 3 3 3 4 7% 59%	6780
	11th to 20th	Day	4 4 1 4 3 3 3 3 4 6% 66%	6463
	21st to end	Day	5% 6% 2 6% 3 3 4 4 6% 7% 54%	6874
August	1st to 10th	Day	4 4 1 5% 4 4 4 3 5% 7% 59%	4541
	11th to 20th	Day	6% 7% 3 8% 5% 5% 5% 4 6% 7% 43%	4311
	21st to end	Day	10% 8% 3 10% 5% 5% 4 3 5% 5% 41%	4413
September	1st to 10th	Day	9% 8% 3 7% 4 4 4 3 3 7% 49%	2400
	11th to 20th	Day	10% 11% 4 10% 5% 4 4 3 5% 5% 39%	2400
	21st to end	Day	13% 13% 5% 8% 4 4 4 3 5% 6% 35%	2140
October	1st to 10th	Day	7% 13% 4 9% 5% 4 5% 5% 7% 8% 33%	3280
	11th to 20th	Day	13% 19% 6% 12% 4 4 4 3 4 5% 26%	3242
	21st to end	Day	8% 21% 8% 14% 7% 6% 4 3 3 5% 20%	3103
November	1st to 10th	Day	9% 23% 7% 13% 7% 6% 6% 4 4 4 17%	1639
	11th to 20th	Day	9% 23% 6% 14% 8% 5% 3 3 4 4 21%	1600
	21st to end	Day	7% 18% 7% 16% 7% 6% 5% 4 5% 6% 19%	1600
December	1st to 10th	Day	4 14% 7% 15% 7% 5% 4 3 5% 7% 29%	2620
	11th to 20th	Day	3 19% 8% 19% 8% 7% 6% 4 5% 5% 15%	3025
	21st to end	Day	4 20% 8% 19% 8% 7% 7% 4 6% 5% 12%	3572
January	1st to 10th	Night	4 19% 9% 17% 9% 7% 6% 4 5% 5% 14%	6657
	11th to 20th	Night	4 11% 5% 12% 8% 5% 6% 4 5% 8% 32%	6282
	21st to end	Night	5% 14% 6% 14% 8% 6% 6% 4 5% 6% 27%	6952
February	1st to 10th	Night	6% 22% 7% 18% 8% 5% 5% 3 4 5% 16%	2675
	11th to 20th	Night	4 20% 9% 16% 7% 5% 5% 4 4 5% 22%	2532
	21st to end	Night	5% 21% 7% 16% 9% 7% 5% 4 5% 5% 16%	2035
March	1st to 10th	Night	2 14% 6% 13% 7% 6% 6% 5% 7% 9% 24%	5376
	11th to 20th	Night	2 16% 7% 15% 8% 6% 5% 4 5% 6% 27%	5092
	21st to end	Night	5% 23% 7% 17% 9% 6% 5% 4 5% 4 15%	5165
April	1st to 10th	Night	5% 20% 7% 13% 8% 6% 4 5% 5% 6% 21%	2000
	11th to 20th	Night	6% 18% 6% 12% 7% 6% 6% 3 4 7% 26%	1979
	21st to end	Night	6% 20% 5% 12% 7% 5% 6% 4 5% 7% 23%	1664
May	1st to 10th	Night	6% 14% 5% 10% 5% 5% 4 3 4 4 40%	3640
	11th to 20th	Night	9% 21% 5% 10% 5% 4 4 3 5% 6% 27%	3616
	21st to end	Night	9% 13% 4 12% 6% 6% 6% 4 6% 7% 25%	3972
June	1st to 10th	Night	13% 12% 4 8% 5% 4 5% 3 6% 8% 32%	1544
	11th to 20th	Night	12% 13% 3 9% 6% 6% 5% 4 7% 8% 26%	1400
	21st to end	Night	11% 9% 3 8% 4 5% 4 3 5% 7% 41%	1400
July	1st to 10th	Night	3 5% 2 5% 3 3 3 3 4 7% 62%	3180
	11th to 20th	Night	3 3 1 3 2 2 2 2 3 5% 73%	3492
	21st to end	Night	5% 6% 2 5% 3 2 3 3 4 9% 59%	3969
August	1st to 10th	Night	3 3 1 4 3 4 3 3 5% 6% 64%	2609
	11th to 20th	Night	4 6% 2 7% 4 4 4 4 7% 11% 46%	2739
	21st to end	Night	9% 9% 3 7% 3 4 4 3 5% 7% 44%	3504
September	1st to 10th	Night	7% 7% 3 6% 4 4 4 4 5% 7% 50%	2000
	11th to 20th	Night	11% 10% 4 6% 4 5% 4 4 5% 7% 41%	2000
	21st to end	Night	11% 11% 5% 9% 5% 5% 5% 3 6% 6% 35%	2255
October	1st to 10th	Night	7% 12% 4 10% 5% 5% 5% 3 6% 9% 35%	3920
	11th to 20th	Night	14% 15% 4 10% 6% 4 4 4 4 6% 29%	3873
	21st to end	Night	8% 17% 7% 15% 7% 5% 4 3 5% 5% 25%	4454
November	1st to 10th	Night	10% 19% 7% 15% 7% 6% 5% 4 5% 6% 16%	2656
	11th to 20th	Night	8% 21% 7% 14% 8% 6% 5% 3 4 5% 19%	2800
	21st to end	Night	6% 20% 8% 15% 8% 6% 5% 4 5% 6% 17%	2800
December	1st to 10th	Night	5% 12% 4 13% 8% 6% 5% 4 6% 6% 31%	4560
	11th to 20th	Night	4 19% 9% 18% 10% 7% 5% 4 5% 5% 15%	5180
	21st to end	Night	5% 19% 8% 18% 9% 6% 6% 4 6% 7% 13%	7348

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	39% 36% 10% 11% 3 1	3269
	11th to 20th	Day	32% 29% 14% 15% 8% 2	3640
	21st to end	Day	32% 37% 11% 9% 11%	4004
February	1st to 10th	Day	23% 64% 5% 4 3 1	1722
	11th to 20th	Day	25% 63% 5% 5% 2 1	1764
	21st to end	Day	24% 64% 5% 6% 2	1595
March	1st to 10th	Day	32% 38% 8% 10% 10% 2	4518
	11th to 20th	Day	30% 36% 14% 16% 4	4906
	21st to end	Day	43% 35% 10% 6% 5%	5810
April	1st to 10th	Day	25% 64% 4 6% 1	2400
	11th to 20th	Day	18% 65% 6% 9% 2	2372
	21st to end	Day	23% 63% 5% 6% 3	2733
May	1st to 10th	Day	27% 34% 7% 24% 8%	6320
	11th to 20th	Day	41% 37% 13% 9% 1	6280
	21st to end	Day	36% 37% 14% 11% 2	6904
June	1st to 10th	Day	18% 64% 6% 9% 4	2851
	11th to 20th	Day	20% 64% 5% 7% 4	3000
	21st to end	Day	18% 63% 5% 10% 4	3000
July	1st to 10th	Day	13% 29% 12% 14% 21% 12%	6706
	11th to 20th	Day	11% 28% 10% 19% 21% 12%	6384
	21st to end	Day	18% 30% 13% 21% 15% 3	6681
August	1st to 10th	Day	11% 37% 6% 13% 27% 6%	4524
	11th to 20th	Day	21% 43% 14% 16% 4 2	4353
	21st to end	Day	22% 40% 8% 18% 10% 2	4412
September	1st to 10th	Day	17% 57% 6% 11% 8% 1	2400
	11th to 20th	Day	20% 58% 4 10% 7% 1	2400
	21st to end	Day	20% 58% 9% 9% 4	2140
October	1st to 10th	Day	19% 44% 13% 17% 6%	3280
	11th to 20th	Day	33% 42% 8% 12% 5%	3242
	21st to end	Day	29% 44% 13% 8% 7%	3103
November	1st to 10th	Day	25% 62% 6% 6% 1	1639
	11th to 20th	Day	24% 59% 6% 6% 4 1	1600
	21st to end	Day	22% 60% 5% 7% 3 2	1600
December	1st to 10th	Day	27% 41% 9% 15% 4 4	2620
	11th to 20th	Day	35% 41% 13% 8% 3	3028
	21st to end	Day	43% 35% 11% 9% 2	3572
January	1st to 10th	Night	40% 38% 9% 9% 3 1	6657
	11th to 20th	Night	28% 31% 15% 15% 10% 2	6320
	21st to end	Night	32% 38% 10% 11% 7% 1	6952
February	1st to 10th	Night	26% 64% 4 3 3 1	2675
	11th to 20th	Night	24% 63% 4 6% 2 1	2534
	21st to end	Night	23% 63% 4 9% 1	2035
March	1st to 10th	Night	21% 39% 11% 16% 12% 1	5376
	11th to 20th	Night	25% 36% 14% 19% 6%	5093
	21st to end	Night	42% 37% 10% 8% 3	5165
April	1st to 10th	Night	19% 66% 6% 8% 2	2000
	11th to 20th	Night	18% 64% 9% 8% 2	1979
	21st to end	Night	19% 64% 6% 7% 3	1664
May	1st to 10th	Night	25% 34% 10% 21% 10%	3637
	11th to 20th	Night	36% 36% 14% 13% 1	3616
	21st to end	Night	29% 41% 16% 11% 2	3972
June	1st to 10th	Night	12% 64% 10% 10% 4	1544
	11th to 20th	Night	13% 64% 6% 11% 6%	1400
	21st to end	Night	14% 63% 8% 13% 2 1	1400
July	1st to 10th	Night	10% 28% 13% 18% 23% 9%	3145
	11th to 20th	Night	9% 26% 13% 17% 24% 10%	3448
	21st to end	Night	16% 28% 12% 26% 12% 6%	3857
August	1st to 10th	Night	9% 37% 6% 21% 25% 2	2601
	11th to 20th	Night	14% 45% 18% 17% 5% 1	2763
	21st to end	Night	20% 40% 13% 16% 10% 1	3504
September	1st to 10th	Night	14% 58% 8% 12% 7% 1	2000
	11th to 20th	Night	17% 59% 6% 11% 6% 1	2000
	21st to end	Night	19% 60% 8% 10% 3	2255
October	1st to 10th	Night	20% 42% 15% 18% 5%	3920
	11th to 20th	Night	28% 41% 11% 12% 8%	3873
	21st to end	Night	27% 44% 13% 11% 5% 1	4454
November	1st to 10th	Night	27% 60% 7% 4 2	2656
	11th to 20th	Night	21% 62% 7% 6% 3 1	2800
	21st to end	Night	23% 60% 6% 5% 4 2	2800
December	1st to 10th	Night	20% 42% 14% 13% 8% 3	4560
	11th to 20th	Night	38% 40% 8% 12% 2	5176
	21st to end	Night	37% 37% 14% 9% 3	7348

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	16% 25% 28% 23% 8% 2	200
	11th to 20th	Day	13% 18% 35% 24% 10% 2	200
	21st to end	Day	11% 26% 32% 24% 7%	220
February	1st to 10th	Day	17% 28% 38% 13% 4	322
	11th to 20th	Day	17% 24% 38% 16% 4 1	395
	21st to end	Day	21% 25% 35% 13% 5% 1	387
March	1st to 10th	Day	18% 31% 29% 16% 5%	500
	11th to 20th	Day	20% 26% 26% 19% 8% 1	500
	21st to end	Day	22% 30% 27% 14% 6%	550
April	1st to 10th	Day	22% 28% 30% 15% 5% 1	500
	11th to 20th	Day	21% 27% 26% 17% 6% 1	492
	21st to end	Day	23% 24% 29% 15% 6% 2	500
May	1st to 10th	Day	17% 24% 31% 21% 6% 1	503
	11th to 20th	Day	24% 18% 27% 20% 9% 2	528
	21st to end	Day	25% 19% 28% 20% 7% 2	573
June	1st to 10th	Day	19% 26% 29% 19% 5% 1	581
	11th to 20th	Day	23% 26% 32% 13% 5% 1	730
	21st to end	Day	15% 21% 32% 21% 10% 1	730
July	1st to 10th	Day	11% 18% 38% 25% 8% 1	721
	11th to 20th	Day	9% 17% 38% 25% 9% 2	585
	21st to end	Day	7% 15% 34% 30% 10% 4	575
August	1st to 10th	Day	9% 11% 31% 32% 13% 4	527
	11th to 20th	Day	7% 15% 29% 32% 13% 3	517
	21st to end	Day	11% 18% 30% 25% 12% 3	583
September	1st to 10th	Day	12% 18% 29% 24% 12% 4	530
	11th to 20th	Day	15% 19% 27% 26% 11% 1	530
	21st to end	Day	24% 22% 28% 17% 8% 2	530
October	1st to 10th	Day	17% 22% 30% 18% 11% 2	530
	11th to 20th	Day	24% 22% 24% 20% 8% 2	523
	21st to end	Day	25% 18% 30% 20% 5% 2	332
November	1st to 10th	Day	22% 21% 32% 20% 4 1	237
	11th to 20th	Day	24% 21% 31% 13% 10% 3	200
	21st to end	Day	15% 18% 37% 19% 7% 5%	200
December	1st to 10th	Day	14% 17% 30% 21% 14% 5%	200
	11th to 20th	Day	16% 20% 40% 18% 7% 1	200
	21st to end	Day	15% 15% 41% 20% 8%	220
January	1st to 10th	Night	15% 21% 35% 21% 7% 1	877
	11th to 20th	Night	10% 16% 43% 21% 10%	800
	21st to end	Night	10% 15% 42% 25% 6% 2	880
February	1st to 10th	Night	14% 18% 37% 24% 6% 1	800
	11th to 20th	Night	9% 15% 39% 28% 9%	784
	21st to end	Night	15% 18% 34% 22% 9% 1	660
March	1st to 10th	Night	11% 17% 34% 27% 10% 1	800
	11th to 20th	Night	9% 20% 37% 26% 8% 1	800
	21st to end	Night	11% 21% 35% 25% 8% 1	880
April	1st to 10th	Night	13% 15% 33% 28% 10% 1	800
	11th to 20th	Night	11% 17% 36% 25% 11% 1	791
	21st to end	Night	12% 14% 31% 31% 9% 2	464
May	1st to 10th	Night	10% 11% 28% 37% 14% 1	400
	11th to 20th	Night	15% 10% 16% 38% 20% 1	394
	21st to end	Night	15% 6% 24% 36% 18% 1	433
June	1st to 10th	Night	12% 9% 34% 32% 13% 1	400
	11th to 20th	Night	12% 14% 28% 32% 13% 1	400
	21st to end	Night	13% 7% 22% 42% 16% 2	400
July	1st to 10th	Night	6% 7% 23% 41% 23% 1	390
	11th to 20th	Night	4 6% 26% 41% 22% 1	388
	21st to end	Night	4 4 20% 45% 26% 1	438
August	1st to 10th	Night	4 4 14% 41% 35% 1	398
	11th to 20th	Night	6% 3 16% 40% 31% 4	493
	21st to end	Night	9% 8% 22% 38% 22% 1	815
September	1st to 10th	Night	8% 8% 24% 35% 21% 5%	800
	11th to 20th	Night	12% 9% 22% 29% 23% 6%	800
	21st to end	Night	14% 13% 31% 27% 14% 2	800
October	1st to 10th	Night	13% 13% 27% 31% 15% 1	800
	11th to 20th	Night	13% 18% 30% 26% 12% 1	792
	21st to end	Night	16% 19% 34% 22% 8% 1	836
November	1st to 10th	Night	13% 18% 43% 22% 3	780
	11th to 20th	Night	18% 21% 34% 19% 7% 1	800
	21st to end	Night	11% 19% 38% 20% 9% 3	800
December	1st to 10th	Night	12% 13% 37% 26% 11% 1	800
	11th to 20th	Night	12% 18% 41% 24% 5% 1	800
	21st to end	Night	12% 19% 41% 23% 4	967

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