Muncho Lake Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Muncho Lake Provincial Park clear sky chart from 2005-11-06 to 2025-02-06.

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% 13% 5% 12% 7% 6% 6% 5% 6% 7% 22%	110958
	Night	5% 12% 6% 13% 8% 7% 7% 5% 7% 8% 23%	115909
Transparency	Day	56% 8% 14% 16% 5%	110668
	Night	53% 9% 14% 16% 7% 1	115846
Seeing	Day	21% 12% 22% 23% 16% 5%	17399
	Night	14% 11% 22% 30% 19% 4	25008

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	2 11% 6% 15% 8% 8% 7% 7% 8% 11% 16%	2259
	11th to 20th	Day	1 9% 5% 15% 10% 9% 6% 6% 9% 10% 20%	2444
	21st to end	Day	1 11% 6% 18% 7% 7% 6% 5% 7% 8% 23%	3498
February	1st to 10th	Day	2 12% 6% 11% 8% 6% 6% 5% 8% 8% 27%	1365
	11th to 20th	Day	1 14% 7% 19% 7% 5% 6% 3 6% 7% 25%	1562
	21st to end	Day	1 6% 5% 18% 10% 9% 7% 6% 8% 8% 22%	1413
March	1st to 10th	Day	5% 3 12% 6% 7% 9% 8% 11% 9% 28%	2992
	11th to 20th	Day	1 12% 6% 17% 10% 10% 8% 6% 8% 7% 16%	3490
	21st to end	Day	1 13% 9% 18% 11% 5% 4 3 5% 5% 27%	3880
April	1st to 10th	Day	3 14% 7% 17% 10% 8% 7% 5% 7% 6% 17%	2451
	11th to 20th	Day	2 16% 7% 15% 8% 7% 6% 5% 6% 7% 21%	2447
	21st to end	Day	5% 20% 6% 14% 8% 6% 5% 5% 5% 6% 19%	2719
May	1st to 10th	Day	5% 15% 5% 9% 7% 6% 6% 5% 7% 9% 26%	4740
	11th to 20th	Day	5% 16% 5% 11% 7% 8% 7% 5% 7% 8% 21%	4905
	21st to end	Day	12% 16% 4 8% 6% 6% 5% 5% 6% 7% 24%	5723
June	1st to 10th	Day	15% 15% 4 10% 6% 6% 5% 4 7% 7% 20%	3230
	11th to 20th	Day	19% 14% 4 11% 7% 6% 6% 3 5% 7% 17%	3230
	21st to end	Day	19% 13% 4 10% 6% 6% 6% 4 6% 7% 19%	3230
July	1st to 10th	Day	15% 8% 3 7% 5% 5% 4 4 6% 9% 34%	5380
	11th to 20th	Day	20% 10% 3 9% 6% 7% 6% 5% 6% 8% 20%	5380
	21st to end	Day	24% 11% 3 9% 7% 6% 5% 4 5% 7% 21%	5340
August	1st to 10th	Day	11% 8% 3 7% 5% 5% 6% 4 5% 7% 38%	4719
	11th to 20th	Day	16% 10% 3 8% 6% 5% 6% 4 5% 6% 30%	4542
	21st to end	Day	20% 18% 4 11% 7% 6% 6% 4 5% 5% 16%	4521
September	1st to 10th	Day	19% 16% 5% 9% 6% 4 5% 3 5% 5% 22%	2429
	11th to 20th	Day	13% 17% 4 10% 7% 6% 6% 4 7% 6% 21%	2199
	21st to end	Day	11% 18% 5% 11% 8% 5% 5% 4 6% 6% 20%	2061
October	1st to 10th	Day	6% 18% 5% 12% 7% 6% 6% 5% 7% 8% 21%	3180
	11th to 20th	Day	6% 22% 6% 13% 7% 7% 7% 4 6% 6% 16%	2891
	21st to end	Day	4 14% 11% 11% 7% 6% 6% 5% 6% 6% 24%	2754
November	1st to 10th	Day	3 19% 7% 15% 5% 5% 5% 4 6% 8% 22%	1485
	11th to 20th	Day	1 17% 7% 14% 12% 9% 6% 6% 7% 7% 14%	1230
	21st to end	Day	1 10% 6% 15% 8% 8% 7% 5% 9% 11% 22%	1200
December	1st to 10th	Day	3 20% 6% 13% 9% 10% 7% 5% 8% 7% 13%	1701
	11th to 20th	Day	1 8% 6% 16% 12% 9% 10% 7% 7% 8% 17%	1882
	21st to end	Day	9% 6% 13% 7% 6% 11% 9% 9% 8% 21%	2486
January	1st to 10th	Night	1 9% 5% 14% 11% 7% 8% 7% 8% 9% 20%	7686
	11th to 20th	Night	1 12% 7% 14% 9% 7% 7% 5% 9% 9% 19%	7484
	21st to end	Night	1 13% 11% 17% 8% 6% 6% 5% 7% 7% 20%	7458
February	1st to 10th	Night	2 11% 5% 14% 9% 7% 7% 6% 8% 7% 24%	2925
	11th to 20th	Night	1 10% 7% 17% 8% 6% 5% 5% 6% 8% 26%	2503
	21st to end	Night	1 9% 4 15% 11% 8% 9% 5% 7% 7% 25%	2041
March	1st to 10th	Night	1 7% 4 12% 11% 9% 9% 7% 11% 9% 22%	3873
	11th to 20th	Night	1 11% 7% 16% 11% 10% 7% 5% 6% 7% 20%	3489
	21st to end	Night	1 12% 8% 16% 9% 6% 5% 5% 7% 8% 22%	3773
April	1st to 10th	Night	2 10% 6% 14% 9% 7% 6% 5% 7% 8% 25%	1727
	11th to 20th	Night	2 14% 5% 12% 7% 5% 6% 5% 8% 7% 28%	1682
	21st to end	Night	5% 18% 6% 12% 6% 5% 6% 6% 6% 8% 24%	1458
May	1st to 10th	Night	5% 11% 4 9% 7% 7% 7% 6% 6% 9% 30%	2220
	11th to 20th	Night	5% 14% 5% 14% 8% 6% 5% 4 6% 7% 26%	1989
	21st to end	Night	12% 15% 3 10% 5% 5% 5% 4 6% 8% 26%	1849
June	1st to 10th	Night	13% 11% 3 8% 7% 6% 7% 6% 7% 7% 27%	950
	11th to 20th	Night	16% 11% 4 8% 6% 5% 6% 5% 8% 8% 24%	950
	21st to end	Night	17% 9% 4 6% 6% 4 5% 5% 8% 8% 27%	950
July	1st to 10th	Night	13% 7% 2 4 5% 4 4 4 5% 11% 42%	1580
	11th to 20th	Night	14% 8% 3 7% 5% 5% 6% 4 8% 11% 29%	1580
	21st to end	Night	16% 11% 4 9% 7% 6% 7% 5% 7% 6% 24%	2209
August	1st to 10th	Night	8% 6% 2 4 4 3 4 3 5% 6% 53%	2211
	11th to 20th	Night	12% 7% 2 6% 4 4 5% 4 6% 7% 42%	2283
	21st to end	Night	24% 14% 4 10% 6% 5% 5% 4 5% 5% 17%	3146
September	1st to 10th	Night	13% 13% 4 9% 5% 5% 5% 4 6% 7% 28%	1751
	11th to 20th	Night	11% 14% 3 10% 6% 5% 6% 6% 7% 9% 24%	1978
	21st to end	Night	10% 16% 4 9% 6% 6% 6% 5% 7% 8% 23%	2119
October	1st to 10th	Night	7% 18% 5% 12% 7% 7% 6% 4 6% 6% 23%	3800
	11th to 20th	Night	6% 17% 6% 12% 6% 6% 6% 4 6% 8% 22%	4037
	21st to end	Night	5% 15% 9% 14% 7% 8% 7% 5% 7% 7% 16%	4794
November	1st to 10th	Night	4 17% 6% 13% 7% 6% 6% 4 6% 8% 23%	2810
	11th to 20th	Night	2 13% 8% 16% 10% 7% 8% 4 7% 8% 16%	3150
	21st to end	Night	2 12% 6% 14% 8% 7% 7% 7% 7% 8% 22%	3200
December	1st to 10th	Night	3 16% 4 13% 9% 8% 7% 7% 10% 8% 16%	5474
	11th to 20th	Night	1 11% 8% 15% 9% 9% 9% 6% 8% 8% 18%	6310
	21st to end	Night	1 9% 5% 14% 8% 8% 9% 7% 8% 9% 22%	8470

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	56% 9% 9% 11% 11% 4	2259
	11th to 20th	Day	54% 7% 13% 14% 12% 1	2460
	21st to end	Day	55% 9% 13% 15% 8% 1	3498
February	1st to 10th	Day	50% 8% 12% 17% 11% 1	1365
	11th to 20th	Day	56% 9% 13% 15% 6% 1	1570
	21st to end	Day	54% 9% 12% 18% 6% 2	1413
March	1st to 10th	Day	41% 8% 7% 28% 15% 1	2992
	11th to 20th	Day	60% 8% 10% 18% 4	3490
	21st to end	Day	59% 6% 13% 16% 6%	3880
April	1st to 10th	Day	64% 7% 10% 15% 4	2451
	11th to 20th	Day	60% 6% 11% 17% 5%	2447
	21st to end	Day	64% 6% 13% 14% 3	2719
May	1st to 10th	Day	51% 7% 17% 17% 8%	4740
	11th to 20th	Day	59% 5% 14% 17% 5%	4909
	21st to end	Day	56% 7% 12% 20% 5%	5724
June	1st to 10th	Day	60% 6% 14% 17% 3	3230
	11th to 20th	Day	65% 6% 12% 13% 3	3230
	21st to end	Day	62% 7% 15% 13% 2	3230
July	1st to 10th	Day	44% 8% 21% 24% 3	5296
	11th to 20th	Day	57% 11% 22% 10% 1	5287
	21st to end	Day	59% 9% 14% 16% 2	5170
August	1st to 10th	Day	42% 7% 13% 23% 14%	4701
	11th to 20th	Day	49% 9% 16% 21% 6%	4587
	21st to end	Day	68% 8% 12% 10% 2	4520
September	1st to 10th	Day	63% 8% 11% 13% 4	2429
	11th to 20th	Day	61% 7% 14% 16% 1	2199
	21st to end	Day	62% 8% 13% 14% 3	2061
October	1st to 10th	Day	56% 10% 17% 13% 4	3180
	11th to 20th	Day	66% 9% 13% 11% 2	2891
	21st to end	Day	55% 9% 18% 14% 4	2754
November	1st to 10th	Day	58% 7% 13% 16% 5% 1	1485
	11th to 20th	Day	65% 8% 10% 12% 5%	1230
	21st to end	Day	53% 8% 15% 16% 7% 2	1200
December	1st to 10th	Day	63% 10% 10% 14% 2	1701
	11th to 20th	Day	57% 12% 10% 15% 6%	1884
	21st to end	Day	44% 15% 17% 16% 7% 2	2486
January	1st to 10th	Night	52% 9% 11% 13% 10% 4	7686
	11th to 20th	Night	55% 8% 9% 12% 13% 2	7530
	21st to end	Night	58% 8% 14% 14% 6%	7458
February	1st to 10th	Night	54% 8% 8% 17% 12% 1	2925
	11th to 20th	Night	53% 7% 15% 15% 9% 1	2506
	21st to end	Night	54% 7% 11% 17% 9% 2	2041
March	1st to 10th	Night	48% 8% 8% 19% 16% 1	3873
	11th to 20th	Night	58% 9% 10% 17% 7%	3490
	21st to end	Night	54% 8% 11% 19% 7%	3773
April	1st to 10th	Night	54% 7% 13% 22% 5%	1727
	11th to 20th	Night	50% 7% 14% 19% 9%	1682
	21st to end	Night	55% 8% 16% 18% 3	1458
May	1st to 10th	Night	43% 13% 15% 23% 5% 1	2220
	11th to 20th	Night	57% 4 17% 15% 6%	1989
	21st to end	Night	54% 6% 11% 22% 7%	1849
June	1st to 10th	Night	53% 7% 15% 22% 3	950
	11th to 20th	Night	54% 8% 16% 19% 3	950
	21st to end	Night	50% 9% 22% 17% 3	950
July	1st to 10th	Night	35% 7% 29% 25% 4	1555
	11th to 20th	Night	44% 10% 31% 14% 1	1550
	21st to end	Night	52% 12% 20% 14% 2	2140
August	1st to 10th	Night	31% 5% 16% 29% 19%	2204
	11th to 20th	Night	39% 8% 22% 25% 5% 1	2304
	21st to end	Night	66% 8% 15% 10%	3146
September	1st to 10th	Night	55% 8% 16% 16% 6% 1	1751
	11th to 20th	Night	53% 8% 19% 17% 2	1978
	21st to end	Night	56% 9% 16% 16% 4	2119
October	1st to 10th	Night	58% 9% 14% 17% 3	3800
	11th to 20th	Night	58% 8% 16% 17% 1	4037
	21st to end	Night	60% 11% 14% 12% 4	4794
November	1st to 10th	Night	55% 9% 14% 16% 4 2	2810
	11th to 20th	Night	61% 10% 10% 14% 4	3150
	21st to end	Night	55% 8% 12% 17% 7% 2	3200
December	1st to 10th	Night	57% 11% 13% 14% 6%	5474
	11th to 20th	Night	55% 11% 11% 17% 5%	6307
	21st to end	Night	47% 13% 16% 16% 7% 1	8470

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	13% 6% 19% 34% 21% 10%	200
	11th to 20th	Day	14% 10% 21% 26% 21% 9%	200
	21st to end	Day	21% 15% 18% 26% 17% 3	220
February	1st to 10th	Day	15% 11% 25% 31% 15% 3	190
	11th to 20th	Day	16% 15% 26% 23% 13% 7%	358
	21st to end	Day	9% 16% 29% 26% 14% 6%	307
March	1st to 10th	Day	8% 13% 31% 24% 17% 8%	384
	11th to 20th	Day	12% 12% 31% 26% 13% 6%	460
	21st to end	Day	11% 15% 27% 26% 16% 5%	506
April	1st to 10th	Day	14% 13% 33% 24% 11% 5%	460
	11th to 20th	Day	14% 12% 31% 23% 15% 6%	452
	21st to end	Day	19% 15% 29% 20% 12% 5%	519
May	1st to 10th	Day	19% 12% 28% 19% 17% 4	653
	11th to 20th	Day	15% 7% 21% 27% 22% 8%	793
	21st to end	Day	18% 8% 19% 24% 22% 9%	940
June	1st to 10th	Day	23% 9% 19% 24% 19% 6%	870
	11th to 20th	Day	27% 10% 17% 25% 16% 5%	870
	21st to end	Day	21% 11% 17% 22% 22% 7%	870
July	1st to 10th	Day	26% 6% 18% 26% 18% 6%	856
	11th to 20th	Day	29% 10% 17% 20% 17% 7%	852
	21st to end	Day	28% 11% 20% 22% 16% 4	802
August	1st to 10th	Day	23% 8% 18% 25% 18% 7%	676
	11th to 20th	Day	33% 16% 24% 16% 9% 2	618
	21st to end	Day	32% 16% 19% 18% 12% 4	539
September	1st to 10th	Day	33% 18% 18% 19% 9% 4	490
	11th to 20th	Day	25% 13% 25% 21% 13% 3	490
	21st to end	Day	32% 19% 24% 15% 8% 2	490
October	1st to 10th	Day	28% 18% 22% 20% 11% 1	490
	11th to 20th	Day	22% 18% 30% 17% 11% 2	404
	21st to end	Day	15% 17% 22% 26% 15% 5%	220
November	1st to 10th	Day	18% 13% 22% 25% 19% 5%	200
	11th to 20th	Day	9% 15% 22% 31% 17% 7%	200
	21st to end	Day	13% 13% 24% 30% 12% 9%	200
December	1st to 10th	Day	11% 19% 26% 24% 18% 4	200
	11th to 20th	Day	11% 12% 26% 32% 15% 5%	200
	21st to end	Day	10% 6% 19% 33% 24% 9%	220
January	1st to 10th	Night	7% 11% 27% 34% 18% 3	1100
	11th to 20th	Night	13% 16% 24% 30% 15% 3	1038
	21st to end	Night	14% 15% 27% 28% 14% 2	990
February	1st to 10th	Night	11% 13% 22% 35% 17% 3	875
	11th to 20th	Night	9% 11% 28% 33% 17% 2	792
	21st to end	Night	6% 11% 21% 38% 21% 3	628
March	1st to 10th	Night	6% 10% 28% 33% 18% 5%	760
	11th to 20th	Night	7% 10% 31% 35% 16% 2	760
	21st to end	Night	8% 9% 23% 31% 22% 8%	836
April	1st to 10th	Night	10% 10% 21% 29% 24% 6%	587
	11th to 20th	Night	11% 7% 19% 32% 25% 6%	554
	21st to end	Night	17% 8% 21% 30% 21% 2	380
May	1st to 10th	Night	16% 8% 18% 32% 22% 4	380
	11th to 20th	Night	16% 4 13% 32% 32% 3	374
	21st to end	Night	18% 6% 11% 27% 30% 9%	411
June	1st to 10th	Night	18% 5% 13% 30% 31% 3	380
	11th to 20th	Night	21% 6% 13% 25% 31% 4	380
	21st to end	Night	21% 6% 14% 20% 35% 4	380
July	1st to 10th	Night	21% 6% 12% 29% 27% 4	370
	11th to 20th	Night	22% 7% 14% 24% 29% 4	368
	21st to end	Night	14% 7% 16% 29% 31% 4	416
August	1st to 10th	Night	18% 5% 12% 22% 37% 6%	378
	11th to 20th	Night	21% 11% 19% 30% 17% 2	377
	21st to end	Night	28% 10% 13% 23% 22% 3	627
September	1st to 10th	Night	23% 12% 18% 26% 19% 4	611
	11th to 20th	Night	19% 13% 19% 27% 17% 4	760
	21st to end	Night	24% 19% 20% 24% 11% 2	760
October	1st to 10th	Night	23% 13% 21% 29% 13% 1	760
	11th to 20th	Night	18% 17% 25% 27% 11% 2	760
	21st to end	Night	16% 12% 24% 29% 16% 4	836
November	1st to 10th	Night	15% 12% 22% 32% 16% 2	820
	11th to 20th	Night	11% 14% 24% 30% 18% 4	1050
	21st to end	Night	14% 11% 27% 32% 15% 2	1100
December	1st to 10th	Night	14% 15% 27% 29% 12% 2	1100
	11th to 20th	Night	10% 11% 24% 35% 16% 5%	1100
	21st to end	Night	8% 12% 21% 32% 21% 6%	1210

Page generated at 2025-02-03 01:05:51. Version ac07

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