Rondeau Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rondeau Provincial Park clear sky chart from 2005-11-06 to 2024-09-14.

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	14% 9% 3 8% 5% 5% 5% 4 6% 7% 35%	101049
	Night	15% 10% 3 8% 5% 4 4 4 5% 7% 34%	96710
Transparency	Day	46% 8% 13% 21% 11% 2	100854
	Night	50% 8% 10% 19% 12% 1	96577
Seeing	Day	16% 7% 21% 31% 20% 5%	14884
	Night	20% 8% 24% 29% 16% 3	24113

By Month

Percentage Cloud Cover SE (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	18% 16% 7% 15% 7% 5% 5% 4 4 5% 14%	2628
	11th to 20th	Day	14% 21% 8% 13% 9% 10% 5% 3 3 3 10%	2840
	21st to end	Day	25% 16% 6% 12% 6% 5% 5% 3 4 3 13%	3124
February	1st to 10th	Day	15% 16% 4 10% 8% 5% 5% 3 5% 5% 23%	1710
	11th to 20th	Day	14% 10% 4 11% 8% 6% 6% 4 5% 5% 26%	1710
	21st to end	Day	17% 11% 4 10% 6% 5% 5% 4 6% 6% 28%	1570
March	1st to 10th	Day	20% 10% 4 9% 6% 5% 5% 4 4 5% 28%	3312
	11th to 20th	Day	12% 10% 4 9% 6% 5% 5% 4 6% 7% 33%	3480
	21st to end	Day	17% 8% 3 8% 5% 5% 5% 4 5% 6% 34%	3815
April	1st to 10th	Day	14% 9% 3 7% 5% 5% 5% 3 6% 8% 33%	2133
	11th to 20th	Day	17% 8% 3 6% 4 4 5% 4 6% 7% 35%	2442
	21st to end	Day	17% 8% 3 8% 5% 5% 5% 3 6% 6% 35%	2470
May	1st to 10th	Day	16% 8% 3 8% 4 5% 6% 4 5% 7% 35%	4082
	11th to 20th	Day	17% 9% 3 7% 5% 5% 6% 4 6% 9% 30%	4081
	21st to end	Day	9% 5% 2 6% 5% 4 4 4 6% 8% 46%	4635
June	1st to 10th	Day	10% 6% 2 6% 5% 4 5% 5% 8% 9% 40%	2660
	11th to 20th	Day	8% 4 3 6% 5% 4 5% 5% 7% 10% 43%	2829
	21st to end	Day	10% 5% 2 6% 4 4 4 4 7% 11% 44%	2850
July	1st to 10th	Day	9% 5% 2 6% 5% 4 5% 4 6% 9% 46%	4547
	11th to 20th	Day	8% 5% 1 5% 4 3 5% 3 6% 9% 51%	4200
	21st to end	Day	7% 4 2 5% 5% 5% 5% 5% 6% 9% 46%	4466
August	1st to 10th	Day	13% 5% 2 5% 4 3 4 4 6% 9% 44%	4104
	11th to 20th	Day	7% 5% 2 6% 4 4 6% 5% 7% 10% 42%	4044
	21st to end	Day	9% 4 2 6% 4 5% 6% 4 7% 9% 44%	4505
September	1st to 10th	Day	10% 6% 2 5% 4 4 5% 4 6% 7% 46%	2174
	11th to 20th	Day	9% 4 2 4 4 4 5% 4 6% 10% 47%	2014
	21st to end	Day	16% 5% 3 5% 4 5% 5% 3 6% 7% 41%	1980
October	1st to 10th	Day	13% 6% 2 7% 5% 5% 5% 3 6% 6% 42%	1868
	11th to 20th	Day	17% 8% 3 8% 5% 5% 5% 4 5% 7% 33%	1800
	21st to end	Day	22% 9% 3 8% 5% 4 5% 4 5% 7% 28%	1931
November	1st to 10th	Day	12% 10% 3 7% 6% 5% 5% 4 6% 7% 36%	1672
	11th to 20th	Day	16% 12% 3 8% 5% 4 5% 4 6% 6% 31%	1646
	21st to end	Day	19% 15% 5% 9% 5% 3 5% 4 5% 7% 22%	1520
December	1st to 10th	Day	18% 17% 5% 10% 6% 5% 5% 4 6% 7% 18%	1520
	11th to 20th	Day	18% 16% 6% 11% 5% 4 5% 4 6% 6% 19%	1910
	21st to end	Day	28% 19% 7% 10% 5% 4 4 3 4 5% 11%	2777
January	1st to 10th	Night	17% 15% 5% 11% 6% 6% 5% 3 4 6% 22%	4292
	11th to 20th	Night	15% 20% 8% 15% 5% 6% 9% 4 4 3 12%	4120
	21st to end	Night	26% 17% 7% 10% 6% 4 4 3 4 4 17%	4532
February	1st to 10th	Night	17% 14% 5% 11% 6% 5% 4 3 5% 5% 24%	2470
	11th to 20th	Night	16% 13% 4 9% 6% 6% 4 4 6% 6% 26%	2352
	21st to end	Night	20% 11% 3 8% 5% 5% 5% 5% 5% 5% 27%	1884
March	1st to 10th	Night	19% 12% 3 7% 6% 4 4 3 4 6% 32%	3541
	11th to 20th	Night	10% 8% 3 7% 5% 4 5% 4 6% 7% 40%	3480
	21st to end	Night	16% 10% 3 7% 4 4 4 3 5% 5% 39%	3817
April	1st to 10th	Night	16% 11% 3 7% 5% 5% 3 3 5% 7% 35%	2054
	11th to 20th	Night	18% 7% 3 6% 5% 5% 4 3 5% 8% 36%	1692
	21st to end	Night	16% 8% 3 7% 5% 4 5% 4 5% 7% 37%	1710
May	1st to 10th	Night	18% 8% 3 8% 4 4 4 4 6% 7% 34%	2813
	11th to 20th	Night	12% 9% 3 9% 5% 5% 5% 5% 6% 7% 33%	2812
	21st to end	Night	10% 5% 2 5% 3 5% 5% 4 5% 8% 49%	2902
June	1st to 10th	Night	11% 5% 3 6% 5% 5% 4 3 6% 8% 45%	1520
	11th to 20th	Night	10% 5% 2 5% 5% 4 4 4 8% 8% 44%	1344
	21st to end	Night	9% 6% 2 5% 5% 5% 5% 4 5% 8% 47%	1330
July	1st to 10th	Night	8% 4 1 5% 4 3 4 4 6% 11% 51%	2418
	11th to 20th	Night	8% 5% 1 5% 3 3 3 4 6% 9% 53%	2746
	21st to end	Night	6% 4 1 6% 4 5% 4 5% 7% 10% 49%	3087
August	1st to 10th	Night	12% 6% 1 6% 4 4 4 4 6% 8% 44%	2825
	11th to 20th	Night	7% 4 2 7% 4 4 5% 4 6% 8% 49%	2785
	21st to end	Night	8% 5% 2 6% 5% 5% 4 4 6% 8% 48%	3124
September	1st to 10th	Night	10% 6% 3 5% 4 4 4 3 5% 8% 46%	1998
	11th to 20th	Night	10% 5% 2 5% 4 3 4 3 5% 8% 52%	2024
	21st to end	Night	16% 6% 3 6% 4 4 4 4 5% 7% 42%	1980
October	1st to 10th	Night	15% 6% 2 6% 4 4 4 4 6% 7% 44%	2092
	11th to 20th	Night	18% 7% 3 8% 5% 4 4 4 5% 7% 35%	2160
	21st to end	Night	23% 8% 3 7% 6% 5% 4 3 5% 6% 30%	2423
November	1st to 10th	Night	14% 8% 2 7% 5% 4 3 4 6% 6% 41%	2406
	11th to 20th	Night	17% 10% 3 8% 5% 5% 5% 4 5% 7% 30%	2531
	21st to end	Night	21% 13% 4 8% 5% 4 4 3 5% 6% 27%	2660
December	1st to 10th	Night	20% 16% 5% 9% 5% 5% 4 4 5% 6% 20%	2660
	11th to 20th	Night	18% 15% 4 10% 6% 4 4 4 5% 5% 24%	3285
	21st to end	Night	27% 20% 6% 11% 6% 5% 4 3 4 4 12%	4841

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	71% 13% 6% 7% 2	2629
	11th to 20th	Day	76% 10% 7% 5% 1	2840
	21st to end	Day	74% 7% 9% 7% 3	3124
February	1st to 10th	Day	62% 7% 10% 14% 5% 1	1710
	11th to 20th	Day	58% 6% 11% 16% 8% 1	1719
	21st to end	Day	55% 7% 13% 18% 6% 2	1570
March	1st to 10th	Day	56% 7% 10% 22% 5%	3312
	11th to 20th	Day	47% 7% 17% 20% 8% 1	3480
	21st to end	Day	48% 7% 13% 21% 10% 2	3815
April	1st to 10th	Day	45% 7% 14% 20% 13% 1	2133
	11th to 20th	Day	46% 7% 12% 20% 14% 1	2442
	21st to end	Day	48% 6% 12% 21% 10% 3	2470
May	1st to 10th	Day	46% 8% 11% 23% 11% 2	4120
	11th to 20th	Day	44% 11% 16% 20% 8% 1	4085
	21st to end	Day	33% 9% 13% 21% 17% 8%	4649
June	1st to 10th	Day	37% 8% 15% 25% 14% 2	2660
	11th to 20th	Day	34% 8% 15% 23% 17% 2	2829
	21st to end	Day	32% 8% 15% 26% 16% 2	2850
July	1st to 10th	Day	33% 7% 13% 27% 17% 3	4478
	11th to 20th	Day	27% 6% 16% 33% 16% 1	4128
	21st to end	Day	32% 8% 18% 21% 19% 3	4324
August	1st to 10th	Day	35% 7% 16% 26% 14% 1	4091
	11th to 20th	Day	34% 8% 16% 32% 8% 1	4083
	21st to end	Day	33% 8% 15% 30% 13% 2	4505
September	1st to 10th	Day	35% 7% 16% 25% 14% 2	2174
	11th to 20th	Day	31% 8% 16% 29% 15%	2014
	21st to end	Day	42% 8% 12% 24% 13% 1	1980
October	1st to 10th	Day	43% 8% 11% 22% 14% 1	1868
	11th to 20th	Day	51% 7% 15% 17% 10% 1	1800
	21st to end	Day	56% 9% 12% 15% 8% 1	1931
November	1st to 10th	Day	48% 8% 12% 20% 10% 2	1672
	11th to 20th	Day	54% 8% 13% 15% 8% 1	1646
	21st to end	Day	64% 9% 9% 14% 4	1520
December	1st to 10th	Day	69% 9% 10% 10% 3	1520
	11th to 20th	Day	66% 8% 12% 9% 5%	1906
	21st to end	Day	78% 6% 8% 6% 1	2777
January	1st to 10th	Night	64% 12% 8% 12% 4	4292
	11th to 20th	Night	70% 15% 6% 7% 2	4120
	21st to end	Night	73% 6% 7% 11% 3	4532
February	1st to 10th	Night	63% 6% 10% 15% 4 1	2470
	11th to 20th	Night	59% 6% 9% 17% 8% 1	2354
	21st to end	Night	57% 6% 10% 18% 8% 1	1884
March	1st to 10th	Night	54% 5% 13% 20% 8%	3541
	11th to 20th	Night	41% 8% 15% 19% 15% 1	3480
	21st to end	Night	46% 7% 9% 20% 16% 1	3817
April	1st to 10th	Night	50% 5% 11% 19% 13% 2	2054
	11th to 20th	Night	47% 6% 10% 21% 14% 2	1692
	21st to end	Night	46% 6% 9% 20% 15% 4	1710
May	1st to 10th	Night	47% 7% 8% 19% 14% 4	2840
	11th to 20th	Night	46% 9% 10% 21% 12% 2	2813
	21st to end	Night	32% 8% 11% 24% 23% 3	2909
June	1st to 10th	Night	36% 8% 11% 26% 16% 4	1520
	11th to 20th	Night	34% 8% 13% 24% 18% 3	1344
	21st to end	Night	35% 7% 11% 26% 20% 1	1330
July	1st to 10th	Night	28% 6% 11% 28% 20% 6%	2378
	11th to 20th	Night	28% 6% 14% 30% 21% 2	2696
	21st to end	Night	29% 9% 16% 22% 22% 3	2988
August	1st to 10th	Night	37% 8% 12% 26% 15% 2	2814
	11th to 20th	Night	32% 9% 12% 31% 15% 1	2812
	21st to end	Night	33% 7% 12% 30% 17% 1	3124
September	1st to 10th	Night	36% 7% 12% 26% 17% 3	1998
	11th to 20th	Night	32% 8% 10% 30% 20% 1	2024
	21st to end	Night	43% 7% 10% 25% 14% 1	1980
October	1st to 10th	Night	40% 9% 11% 21% 19% 1	2092
	11th to 20th	Night	50% 8% 10% 18% 14%	2160
	21st to end	Night	56% 7% 11% 16% 9% 1	2423
November	1st to 10th	Night	46% 7% 10% 21% 14% 1	2406
	11th to 20th	Night	55% 10% 9% 16% 8% 1	2531
	21st to end	Night	60% 7% 11% 15% 5%	2660
December	1st to 10th	Night	69% 10% 8% 10% 3	2660
	11th to 20th	Night	63% 8% 12% 11% 5%	3288
	21st to end	Night	77% 7% 7% 6% 2	4841

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	23% 11% 36% 20% 9% 1	270
	11th to 20th	Day	26% 12% 39% 17% 5% 1	270
	21st to end	Day	27% 10% 28% 29% 4 1	297
February	1st to 10th	Day	19% 11% 36% 28% 6% 1	270
	11th to 20th	Day	20% 13% 33% 31% 3	270
	21st to end	Day	21% 11% 38% 26% 4	225
March	1st to 10th	Day	18% 11% 30% 33% 9% 1	384
	11th to 20th	Day	15% 11% 29% 35% 8% 1	460
	21st to end	Day	24% 7% 28% 32% 8% 1	506
April	1st to 10th	Day	14% 7% 32% 34% 12% 1	460
	11th to 20th	Day	21% 8% 27% 31% 9% 5%	452
	21st to end	Day	18% 6% 25% 36% 13% 1	460
May	1st to 10th	Day	21% 5% 22% 32% 18% 2	463
	11th to 20th	Day	16% 2 19% 33% 25% 4	487
	21st to end	Day	12% 2 15% 31% 31% 9%	529
June	1st to 10th	Day	11% 4 14% 41% 25% 5%	490
	11th to 20th	Day	10% 1 16% 38% 30% 4	659
	21st to end	Day	12% 3 14% 40% 28% 4	680
July	1st to 10th	Day	7% 3 10% 35% 32% 12%	671
	11th to 20th	Day	12% 3 10% 36% 30% 9%	535
	21st to end	Day	8% 2 9% 34% 39% 7%	532
August	1st to 10th	Day	9% 3 10% 35% 31% 12%	486
	11th to 20th	Day	9% 5% 11% 32% 35% 9%	479
	21st to end	Day	9% 3 13% 32% 33% 11%	539
September	1st to 10th	Day	12% 4 13% 29% 29% 12%	490
	11th to 20th	Day	8% 2 12% 28% 35% 14%	463
	21st to end	Day	16% 6% 20% 27% 22% 9%	450
October	1st to 10th	Day	15% 7% 22% 25% 22% 9%	450
	11th to 20th	Day	18% 13% 27% 29% 11% 2	450
	21st to end	Day	27% 12% 26% 24% 11% 1	446
November	1st to 10th	Day	14% 13% 29% 26% 16% 3	270
	11th to 20th	Day	25% 13% 26% 27% 8% 1	239
	21st to end	Day	27% 12% 34% 24% 3	180
December	1st to 10th	Day	23% 16% 31% 23% 7%	180
	11th to 20th	Day	27% 19% 33% 19% 2	180
	21st to end	Day	28% 20% 29% 19% 4	212
January	1st to 10th	Night	26% 15% 36% 17% 6% 1	866
	11th to 20th	Night	31% 14% 29% 22% 5%	760
	21st to end	Night	25% 10% 31% 27% 7%	836
February	1st to 10th	Night	26% 9% 33% 27% 5%	760
	11th to 20th	Night	22% 11% 29% 31% 7%	743
	21st to end	Night	26% 7% 36% 26% 5%	628
March	1st to 10th	Night	21% 6% 31% 33% 9%	760
	11th to 20th	Night	17% 7% 34% 30% 10% 1	760
	21st to end	Night	20% 7% 29% 31% 11% 2	836
April	1st to 10th	Night	19% 7% 28% 35% 10% 1	760
	11th to 20th	Night	19% 6% 28% 33% 12% 2	568
	21st to end	Night	18% 5% 22% 41% 13% 2	570
May	1st to 10th	Night	17% 5% 22% 34% 20% 3	570
	11th to 20th	Night	17% 4 18% 32% 25% 4	561
	21st to end	Night	12% 1 12% 37% 32% 6%	517
June	1st to 10th	Night	12% 2 19% 40% 23% 4	380
	11th to 20th	Night	12% 1 14% 38% 32% 2	380
	21st to end	Night	9% 3 16% 41% 27% 4	380
July	1st to 10th	Night	7% 2 10% 34% 38% 9%	482
	11th to 20th	Night	11% 3 11% 36% 31% 8%	552
	21st to end	Night	7% 2 13% 36% 37% 5%	624
August	1st to 10th	Night	10% 2 10% 36% 34% 8%	567
	11th to 20th	Night	8% 3 12% 32% 37% 8%	564
	21st to end	Night	10% 3 15% 32% 34% 7%	627
September	1st to 10th	Night	12% 4 15% 27% 31% 10%	755
	11th to 20th	Night	10% 4 13% 28% 35% 10%	736
	21st to end	Night	18% 5% 17% 31% 22% 7%	720
October	1st to 10th	Night	19% 6% 21% 28% 20% 6%	720
	11th to 20th	Night	22% 11% 26% 26% 13% 2	720
	21st to end	Night	28% 13% 26% 27% 6%	792
November	1st to 10th	Night	19% 12% 25% 27% 15% 2	740
	11th to 20th	Night	26% 14% 31% 20% 7% 1	760
	21st to end	Night	28% 16% 28% 20% 7%	760
December	1st to 10th	Night	31% 16% 31% 16% 6% 1	760
	11th to 20th	Night	25% 17% 33% 21% 4	760
	21st to end	Night	32% 12% 30% 23% 3	839

Page generated at 2024-09-11 10:00:06. Version ac07

Copyright © 2024 Attilla Danko.