Pincher Creek
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pincher Creek clear sky chart from 2005-11-06 to 2024-02-10.

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% 7% 3 6% 5% 3 5% 5% 6% 9% 44%	77785
	Night	5% 7% 3 6% 5% 3 5% 5% 6% 9% 45%	81138
Transparency	Day	37% 7% 16% 24% 13% 3	77498
	Night	36% 7% 18% 24% 12% 2	81005
Seeing	Day	19% 18% 27% 22% 11% 3	14207
	Night	16% 19% 30% 24% 10% 1	23585

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 7% 4 10% 6% 4 4 6% 7% 12% 39%	2219
	11th to 20th	Day	2 8% 7% 9% 7% 5% 6% 6% 6% 10% 33%	2367
	21st to end	Day	2 6% 3 6% 6% 3 5% 4 6% 12% 46%	2794
February	1st to 10th	Day	3 9% 5% 9% 7% 5% 5% 5% 7% 10% 34%	1548
	11th to 20th	Day	3 11% 5% 9% 7% 3 5% 6% 7% 9% 34%	1575
	21st to end	Day	2 10% 5% 10% 8% 3 5% 4 6% 8% 37%	1468
March	1st to 10th	Day	2 8% 4 9% 7% 3 5% 5% 7% 9% 41%	1800
	11th to 20th	Day	5% 8% 4 6% 5% 3 5% 5% 7% 10% 44%	1961
	21st to end	Day	6% 11% 4 7% 6% 3 6% 5% 8% 10% 34%	2196
April	1st to 10th	Day	6% 11% 5% 7% 6% 4 6% 6% 7% 10% 34%	2191
	11th to 20th	Day	9% 11% 4 7% 6% 3 5% 5% 7% 8% 35%	2310
	21st to end	Day	11% 12% 3 6% 6% 4 4 6% 6% 9% 36%	2340
May	1st to 10th	Day	10% 11% 4 6% 6% 3 6% 6% 6% 8% 33%	2360
	11th to 20th	Day	14% 7% 2 5% 5% 3 5% 6% 6% 8% 37%	2628
	21st to end	Day	22% 8% 3 6% 6% 3 5% 5% 5% 8% 29%	2917
June	1st to 10th	Day	13% 7% 3 7% 6% 3 6% 5% 6% 8% 37%	2700
	11th to 20th	Day	16% 6% 3 6% 6% 4 7% 6% 6% 7% 32%	2700
	21st to end	Day	7% 3 2 4 4 3 5% 6% 6% 9% 50%	2700
July	1st to 10th	Day	6% 4 2 4 4 3 5% 5% 7% 9% 51%	2700
	11th to 20th	Day	6% 3 2 4 3 3 5% 5% 6% 7% 56%	2700
	21st to end	Day	3 3 1 3 3 2 4 4 5% 7% 65%	2791
August	1st to 10th	Day	8% 4 1 4 3 2 4 4 6% 8% 55%	2490
	11th to 20th	Day	6% 3 1 3 4 2 4 5% 5% 8% 58%	2299
	21st to end	Day	8% 3 2 3 4 3 4 5% 6% 9% 53%	2574
September	1st to 10th	Day	12% 4 2 3 4 2 4 4 6% 7% 53%	2198
	11th to 20th	Day	10% 5% 2 4 5% 2 4 4 5% 7% 52%	1980
	21st to end	Day	10% 6% 1 3 4 2 4 4 5% 7% 53%	1980
October	1st to 10th	Day	12% 9% 3 4 4 2 4 4 5% 7% 45%	1915
	11th to 20th	Day	6% 8% 3 5% 4 3 5% 5% 6% 7% 48%	1690
	21st to end	Day	5% 10% 4 7% 5% 3 4 5% 6% 9% 42%	1782
November	1st to 10th	Day	7% 11% 3 6% 3 3 4 4 7% 11% 41%	1608
	11th to 20th	Day	3 8% 3 6% 4 3 4 5% 6% 10% 48%	1520
	21st to end	Day	2 10% 6% 8% 6% 3 5% 5% 6% 9% 42%	1330
December	1st to 10th	Day	2 8% 5% 7% 7% 3 4 6% 7% 9% 44%	1330
	11th to 20th	Day	4 8% 3 9% 6% 3 5% 5% 7% 11% 39%	1682
	21st to end	Day	3 7% 4 6% 5% 3 4 4 6% 9% 48%	2442
January	1st to 10th	Night	2 8% 5% 8% 6% 3 5% 6% 8% 10% 39%	4726
	11th to 20th	Night	2 9% 5% 9% 7% 4 7% 6% 6% 9% 36%	4559
	21st to end	Night	2 8% 4 7% 5% 4 5% 5% 7% 10% 44%	4862
February	1st to 10th	Night	4 12% 5% 10% 6% 4 5% 5% 6% 9% 35%	2615
	11th to 20th	Night	2 12% 4 8% 5% 4 6% 6% 6% 10% 37%	2272
	21st to end	Night	2 8% 5% 10% 9% 5% 6% 5% 5% 6% 40%	1785
March	1st to 10th	Night	1 8% 5% 10% 7% 4 4 4 6% 9% 41%	2160
	11th to 20th	Night	4 6% 4 6% 5% 3 6% 6% 6% 9% 46%	1998
	21st to end	Night	5% 9% 5% 6% 5% 3 5% 6% 7% 9% 40%	2159
April	1st to 10th	Night	8% 8% 4 7% 5% 3 5% 6% 6% 8% 41%	1768
	11th to 20th	Night	9% 10% 4 6% 5% 3 4 6% 7% 8% 38%	1601
	21st to end	Night	8% 11% 4 6% 6% 3 4 4 6% 8% 40%	1620
May	1st to 10th	Night	10% 8% 4 7% 6% 4 5% 5% 6% 7% 39%	1598
	11th to 20th	Night	10% 6% 3 4 4 3 5% 5% 6% 8% 45%	1263
	21st to end	Night	22% 7% 2 5% 4 2 5% 5% 6% 7% 36%	1358
June	1st to 10th	Night	11% 5% 2 5% 6% 3 6% 4 5% 10% 42%	1260
	11th to 20th	Night	18% 6% 2 4 4 4 4 5% 5% 8% 39%	1260
	21st to end	Night	5% 3 2 4 4 3 4 6% 5% 8% 56%	1260
July	1st to 10th	Night	5% 3 2 2 3 1 3 5% 6% 8% 61%	1260
	11th to 20th	Night	6% 2 1 4 3 2 3 5% 6% 7% 61%	1260
	21st to end	Night	5% 1 1 2 3 2 3 3 4 5% 69%	1523
August	1st to 10th	Night	7% 3 1 3 2 3 4 4 4 8% 60%	1449
	11th to 20th	Night	7% 4 1 2 3 2 2 4 6% 9% 59%	1602
	21st to end	Night	8% 3 1 3 4 2 3 4 5% 7% 60%	1782
September	1st to 10th	Night	10% 5% 1 3 3 2 4 4 5% 6% 56%	1758
	11th to 20th	Night	11% 6% 2 3 3 2 3 3 5% 7% 55%	1980
	21st to end	Night	10% 6% 2 3 3 2 4 4 5% 8% 53%	1980
October	1st to 10th	Night	12% 7% 2 4 3 2 4 4 5% 7% 50%	2044
	11th to 20th	Night	6% 6% 2 4 4 3 4 4 6% 8% 53%	2268
	21st to end	Night	5% 8% 4 7% 6% 3 4 5% 7% 8% 43%	2574
November	1st to 10th	Night	6% 11% 4 6% 5% 3 4 5% 6% 8% 42%	2452
	11th to 20th	Night	2 7% 3 6% 5% 3 4 6% 6% 9% 49%	2660
	21st to end	Night	3 8% 5% 7% 6% 3 5% 4 5% 10% 44%	2848
December	1st to 10th	Night	2 8% 4 8% 6% 3 5% 6% 6% 10% 43%	2850
	11th to 20th	Night	2 7% 5% 8% 8% 4 6% 6% 8% 10% 36%	3510
	21st to end	Night	2 8% 4 6% 6% 4 5% 5% 7% 8% 45%	5214

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	37% 10% 20% 22% 11% 1	2219
	11th to 20th	Day	46% 7% 18% 13% 13% 4	2390
	21st to end	Day	31% 8% 24% 29% 7% 1	2794
February	1st to 10th	Day	46% 6% 18% 20% 8% 2	1548
	11th to 20th	Day	44% 7% 19% 21% 9% 1	1584
	21st to end	Day	45% 7% 15% 20% 12% 1	1468
March	1st to 10th	Day	39% 9% 16% 25% 10% 1	1800
	11th to 20th	Day	35% 8% 17% 27% 11% 2	1962
	21st to end	Day	43% 9% 19% 21% 7% 1	2196
April	1st to 10th	Day	44% 7% 17% 23% 9% 1	2191
	11th to 20th	Day	45% 7% 15% 21% 10% 1	2310
	21st to end	Day	45% 6% 15% 21% 11% 1	2340
May	1st to 10th	Day	47% 6% 15% 24% 9%	2360
	11th to 20th	Day	43% 6% 16% 24% 10% 1	2632
	21st to end	Day	52% 6% 15% 17% 9%	2918
June	1st to 10th	Day	44% 7% 15% 21% 11% 2	2700
	11th to 20th	Day	48% 7% 13% 20% 11% 1	2700
	21st to end	Day	30% 6% 17% 30% 14% 3	2700
July	1st to 10th	Day	28% 6% 13% 29% 18% 6%	2626
	11th to 20th	Day	26% 6% 11% 26% 23% 7%	2619
	21st to end	Day	18% 5% 10% 30% 29% 8%	2636
August	1st to 10th	Day	26% 6% 15% 26% 20% 7%	2473
	11th to 20th	Day	25% 5% 14% 33% 17% 5%	2299
	21st to end	Day	27% 6% 10% 29% 23% 5%	2574
September	1st to 10th	Day	30% 4 12% 28% 18% 8%	2198
	11th to 20th	Day	31% 6% 13% 29% 17% 4	1980
	21st to end	Day	31% 6% 14% 33% 13% 3	1980
October	1st to 10th	Day	37% 6% 18% 26% 11% 2	1915
	11th to 20th	Day	34% 7% 20% 24% 14% 2	1690
	21st to end	Day	38% 7% 17% 25% 11% 1	1782
November	1st to 10th	Day	38% 10% 17% 23% 11%	1608
	11th to 20th	Day	32% 9% 23% 25% 9% 2	1520
	21st to end	Day	38% 8% 22% 20% 9% 3	1330
December	1st to 10th	Day	37% 9% 22% 22% 8% 3	1330
	11th to 20th	Day	37% 10% 23% 23% 6% 1	1684
	21st to end	Day	32% 7% 17% 25% 19% 1	2442
January	1st to 10th	Night	37% 11% 20% 23% 8% 1	4726
	11th to 20th	Night	46% 7% 16% 16% 11% 5%	4598
	21st to end	Night	33% 9% 23% 26% 8% 1	4862
February	1st to 10th	Night	46% 7% 15% 19% 11% 2	2615
	11th to 20th	Night	42% 9% 19% 20% 10%	2273
	21st to end	Night	46% 6% 12% 24% 9% 2	1785
March	1st to 10th	Night	39% 8% 20% 23% 8% 1	2160
	11th to 20th	Night	34% 9% 22% 23% 12% 1	1998
	21st to end	Night	38% 9% 22% 23% 7% 1	2159
April	1st to 10th	Night	39% 8% 17% 25% 10% 2	1768
	11th to 20th	Night	42% 7% 14% 27% 10%	1601
	21st to end	Night	42% 7% 14% 28% 8% 1	1620
May	1st to 10th	Night	43% 6% 15% 25% 11%	1598
	11th to 20th	Night	36% 7% 15% 29% 12% 1	1263
	21st to end	Night	47% 5% 17% 22% 9%	1358
June	1st to 10th	Night	38% 6% 18% 27% 10% 1	1260
	11th to 20th	Night	43% 5% 17% 22% 13%	1260
	21st to end	Night	26% 5% 19% 31% 17% 3	1260
July	1st to 10th	Night	20% 6% 16% 35% 18% 5%	1225
	11th to 20th	Night	22% 5% 14% 26% 24% 8%	1218
	21st to end	Night	17% 4 12% 28% 29% 10%	1438
August	1st to 10th	Night	24% 4 14% 30% 20% 8%	1441
	11th to 20th	Night	22% 5% 15% 33% 22% 4	1602
	21st to end	Night	25% 4 10% 31% 26% 4	1782
September	1st to 10th	Night	28% 6% 11% 32% 17% 7%	1758
	11th to 20th	Night	30% 4 13% 30% 18% 4	1980
	21st to end	Night	29% 5% 18% 29% 16% 3	1980
October	1st to 10th	Night	34% 5% 18% 28% 15% 1	2044
	11th to 20th	Night	29% 7% 18% 29% 15% 3	2268
	21st to end	Night	37% 9% 18% 25% 11% 1	2574
November	1st to 10th	Night	40% 7% 20% 22% 10% 1	2452
	11th to 20th	Night	31% 8% 23% 24% 12% 1	2660
	21st to end	Night	37% 8% 22% 20% 10% 3	2848
December	1st to 10th	Night	37% 9% 20% 21% 11% 3	2850
	11th to 20th	Night	39% 11% 22% 21% 5% 1	3507
	21st to end	Night	35% 6% 20% 22% 14% 4	5214

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	18% 22% 27% 18% 11% 4	180
	11th to 20th	Day	27% 16% 26% 23% 8% 2	180
	21st to end	Day	23% 32% 27% 9% 7% 3	198
February	1st to 10th	Day	29% 13% 31% 18% 8% 1	195
	11th to 20th	Day	23% 24% 24% 21% 8% 1	240
	21st to end	Day	19% 26% 29% 21% 4 1	334
March	1st to 10th	Day	20% 23% 29% 18% 7% 3	420
	11th to 20th	Day	19% 25% 25% 19% 12% 1	420
	21st to end	Day	23% 26% 27% 16% 6% 2	462
April	1st to 10th	Day	22% 25% 30% 17% 6%	420
	11th to 20th	Day	25% 23% 25% 16% 9% 2	412
	21st to end	Day	24% 25% 24% 18% 8% 1	420
May	1st to 10th	Day	19% 19% 27% 21% 12% 4	423
	11th to 20th	Day	26% 12% 23% 23% 14% 3	599
	21st to end	Day	26% 9% 21% 25% 14% 4	679
June	1st to 10th	Day	20% 18% 25% 23% 11% 2	630
	11th to 20th	Day	26% 19% 25% 20% 8% 2	630
	21st to end	Day	11% 12% 30% 27% 16% 4	630
July	1st to 10th	Day	11% 9% 28% 29% 19% 4	621
	11th to 20th	Day	11% 15% 27% 31% 14% 2	618
	21st to end	Day	7% 12% 32% 30% 17% 3	537
August	1st to 10th	Day	12% 11% 29% 31% 15% 3	447
	11th to 20th	Day	8% 9% 33% 29% 16% 5%	437
	21st to end	Day	13% 11% 33% 27% 13% 3	495
September	1st to 10th	Day	18% 20% 24% 22% 13% 4	450
	11th to 20th	Day	18% 11% 35% 21% 12% 4	450
	21st to end	Day	24% 23% 26% 18% 8% 2	450
October	1st to 10th	Day	22% 15% 26% 21% 13% 3	385
	11th to 20th	Day	18% 23% 28% 19% 10% 3	270
	21st to end	Day	26% 24% 25% 15% 8% 2	297
November	1st to 10th	Day	27% 26% 26% 14% 6% 1	270
	11th to 20th	Day	25% 25% 36% 13% 2	270
	21st to end	Day	23% 26% 21% 14% 9% 6%	180
December	1st to 10th	Day	19% 28% 31% 12% 7% 3	180
	11th to 20th	Day	28% 19% 27% 18% 6% 2	180
	21st to end	Day	21% 22% 22% 21% 10% 5%	198
January	1st to 10th	Night	21% 26% 32% 16% 5%	950
	11th to 20th	Night	17% 24% 38% 16% 4 1	860
	21st to end	Night	16% 29% 34% 15% 5% 1	836
February	1st to 10th	Night	17% 21% 30% 22% 7% 2	758
	11th to 20th	Night	19% 26% 28% 21% 6%	704
	21st to end	Night	14% 22% 30% 26% 8% 1	592
March	1st to 10th	Night	13% 22% 31% 24% 8% 2	720
	11th to 20th	Night	16% 21% 29% 25% 7% 1	720
	21st to end	Night	16% 19% 26% 27% 10% 2	792
April	1st to 10th	Night	15% 21% 27% 25% 10% 1	688
	11th to 20th	Night	17% 22% 27% 24% 10%	533
	21st to end	Night	17% 14% 34% 24% 10% 1	540
May	1st to 10th	Night	18% 16% 25% 25% 15%	518
	11th to 20th	Night	17% 8% 25% 31% 17% 2	354
	21st to end	Night	25% 9% 20% 30% 16% 1	389
June	1st to 10th	Night	18% 12% 26% 30% 13% 2	360
	11th to 20th	Night	23% 16% 27% 23% 10% 1	360
	21st to end	Night	7% 12% 34% 28% 18% 1	360
July	1st to 10th	Night	9% 7% 24% 38% 23%	350
	11th to 20th	Night	9% 6% 30% 41% 13% 1	348
	21st to end	Night	6% 5% 29% 40% 20% 1	394
August	1st to 10th	Night	9% 4 22% 39% 24% 1	375
	11th to 20th	Night	8% 5% 26% 36% 22% 1	534
	21st to end	Night	10% 8% 28% 37% 15% 1	594
September	1st to 10th	Night	14% 9% 27% 31% 16% 4	652
	11th to 20th	Night	16% 10% 25% 28% 17% 3	720
	21st to end	Night	16% 15% 30% 25% 10% 3	720
October	1st to 10th	Night	20% 11% 26% 26% 16% 1	720
	11th to 20th	Night	16% 19% 28% 27% 9% 1	720
	21st to end	Night	19% 23% 32% 18% 6% 1	792
November	1st to 10th	Night	24% 22% 29% 20% 4	787
	11th to 20th	Night	22% 29% 33% 13% 3 1	950
	21st to end	Night	16% 31% 31% 16% 5% 1	950
December	1st to 10th	Night	14% 28% 30% 20% 6% 1	950
	11th to 20th	Night	17% 24% 34% 19% 5%	950
	21st to end	Night	18% 23% 34% 17% 7% 1	1045

Page generated at 2024-02-07 04:11:55. Version ac07

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