Peachland
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Peachland clear sky chart from 2005-11-06 to 2024-02-15.

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 8% 7% 4 6% 6% 6% 7% 35%	78113
	Night	9% 12% 4 8% 6% 4 5% 5% 6% 7% 34%	80871
Transparency	Day	45% 7% 16% 19% 10% 2	77831
	Night	47% 7% 17% 19% 9% 1	80733
Seeing	Day	14% 18% 29% 25% 12% 3	14270
	Night	14% 11% 27% 30% 16% 2	22967

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	10% 18% 6% 14% 9% 5% 5% 6% 5% 5% 17%	2321
	11th to 20th	Day	8% 17% 5% 8% 9% 5% 5% 5% 5% 7% 28%	2516
	21st to end	Day	15% 21% 5% 8% 7% 4 5% 5% 5% 6% 17%	2794
February	1st to 10th	Day	7% 14% 5% 12% 10% 4 6% 5% 5% 6% 26%	1572
	11th to 20th	Day	7% 12% 4 8% 7% 4 7% 6% 6% 8% 30%	1612
	21st to end	Day	7% 12% 6% 13% 9% 5% 7% 7% 6% 7% 21%	1453
March	1st to 10th	Day	7% 12% 4 10% 7% 5% 7% 7% 7% 8% 26%	1800
	11th to 20th	Day	6% 14% 5% 9% 9% 5% 6% 6% 6% 7% 27%	1891
	21st to end	Day	6% 12% 6% 10% 8% 6% 7% 7% 7% 8% 23%	2340
April	1st to 10th	Day	10% 11% 5% 9% 8% 5% 7% 6% 6% 9% 25%	2160
	11th to 20th	Day	8% 11% 5% 8% 7% 5% 7% 6% 7% 8% 29%	2138
	21st to end	Day	7% 11% 4 9% 8% 5% 6% 6% 7% 8% 31%	2474
May	1st to 10th	Day	9% 9% 4 8% 7% 4 6% 7% 6% 6% 34%	2520
	11th to 20th	Day	9% 8% 4 8% 7% 4 7% 6% 7% 8% 31%	2477
	21st to end	Day	12% 8% 4 8% 8% 5% 7% 6% 6% 7% 30%	2723
June	1st to 10th	Day	15% 8% 4 8% 7% 5% 5% 5% 5% 8% 29%	2713
	11th to 20th	Day	13% 8% 4 8% 8% 5% 7% 7% 6% 8% 27%	2880
	21st to end	Day	8% 5% 3 6% 7% 4 7% 6% 5% 8% 40%	2880
July	1st to 10th	Day	6% 5% 2 5% 6% 3 6% 6% 6% 7% 47%	2706
	11th to 20th	Day	5% 4 2 5% 5% 3 5% 6% 5% 7% 53%	2566
	21st to end	Day	3 3 1 3 4 3 4 4 5% 7% 63%	2741
August	1st to 10th	Day	4 3 2 4 5% 3 4 5% 6% 8% 56%	2507
	11th to 20th	Day	4 4 2 4 4 3 4 5% 6% 7% 57%	2453
	21st to end	Day	6% 4 2 4 6% 4 6% 6% 6% 8% 47%	2413
September	1st to 10th	Day	6% 5% 3 6% 5% 3 4 4 4 7% 54%	2160
	11th to 20th	Day	9% 7% 2 6% 6% 3 5% 5% 5% 6% 45%	2151
	21st to end	Day	11% 7% 2 5% 5% 3 5% 5% 6% 7% 44%	1952
October	1st to 10th	Day	9% 8% 3 7% 5% 4 5% 5% 5% 7% 42%	1800
	11th to 20th	Day	12% 8% 3 7% 7% 4 5% 6% 6% 7% 36%	1757
	21st to end	Day	13% 9% 4 7% 7% 4 5% 5% 6% 7% 31%	1782
November	1st to 10th	Day	14% 13% 5% 8% 7% 4 5% 5% 7% 7% 25%	1575
	11th to 20th	Day	10% 15% 5% 10% 6% 4 7% 5% 5% 4 28%	1520
	21st to end	Day	10% 14% 7% 9% 8% 3 5% 6% 6% 6% 26%	1435
December	1st to 10th	Day	9% 11% 6% 9% 10% 5% 5% 6% 7% 8% 25%	1330
	11th to 20th	Day	10% 17% 7% 11% 7% 3 6% 5% 6% 6% 23%	1682
	21st to end	Day	10% 15% 6% 12% 10% 6% 6% 6% 6% 5% 18%	2319
January	1st to 10th	Night	11% 19% 7% 13% 9% 4 5% 5% 4 5% 16%	4618
	11th to 20th	Night	9% 16% 7% 11% 6% 3 5% 4 6% 8% 26%	4382
	21st to end	Night	14% 26% 7% 8% 7% 4 5% 4 4 5% 16%	4862
February	1st to 10th	Night	10% 16% 6% 11% 7% 5% 5% 4 5% 6% 24%	2605
	11th to 20th	Night	8% 12% 4 7% 7% 4 5% 4 6% 7% 36%	2329
	21st to end	Night	7% 9% 6% 10% 9% 4 6% 7% 7% 7% 27%	1803
March	1st to 10th	Night	8% 11% 5% 8% 7% 4 7% 6% 6% 6% 31%	2160
	11th to 20th	Night	7% 10% 4 9% 7% 3 5% 5% 5% 7% 37%	2065
	21st to end	Night	7% 9% 4 9% 8% 5% 7% 6% 6% 7% 31%	2016
April	1st to 10th	Night	6% 8% 3 8% 7% 5% 6% 6% 7% 9% 35%	1800
	11th to 20th	Night	5% 8% 4 8% 7% 5% 6% 7% 7% 6% 36%	1772
	21st to end	Night	6% 12% 4 7% 7% 4 5% 5% 6% 7% 37%	1483
May	1st to 10th	Night	7% 7% 3 7% 6% 3 6% 5% 7% 7% 42%	1440
	11th to 20th	Night	8% 4 2 6% 6% 5% 7% 6% 6% 10% 39%	1416
	21st to end	Night	11% 7% 3 7% 6% 3 5% 5% 5% 9% 39%	1552
June	1st to 10th	Night	10% 7% 3 7% 6% 3 4 6% 8% 9% 35%	1238
	11th to 20th	Night	9% 4 3 7% 8% 4 5% 6% 8% 10% 38%	1080
	21st to end	Night	6% 5% 2 6% 6% 4 4 6% 6% 6% 50%	1080
July	1st to 10th	Night	4 3 2 4 5% 2 4 5% 6% 8% 57%	1250
	11th to 20th	Night	3 3 1 3 3 2 5% 6% 5% 9% 60%	1390
	21st to end	Night	3 2 1 2 2 2 3 4 4 6% 72%	1576
August	1st to 10th	Night	3 2 1 3 3 3 3 5% 6% 7% 64%	1432
	11th to 20th	Night	3 3 1 3 3 2 4 4 5% 7% 66%	1444
	21st to end	Night	4 3 1 4 5% 3 4 6% 6% 9% 55%	1942
September	1st to 10th	Night	5% 4 2 4 3 3 4 4 6% 8% 59%	1800
	11th to 20th	Night	7% 5% 2 4 4 3 4 5% 6% 8% 52%	1808
	21st to end	Night	9% 7% 3 5% 5% 3 4 5% 6% 9% 45%	2006
October	1st to 10th	Night	9% 6% 2 5% 5% 3 5% 5% 6% 7% 46%	2160
	11th to 20th	Night	11% 8% 3 6% 6% 4 5% 5% 5% 6% 41%	2202
	21st to end	Night	13% 10% 3 7% 5% 3 4 6% 5% 7% 37%	2574
November	1st to 10th	Night	15% 12% 4 7% 5% 3 6% 6% 6% 7% 29%	2501
	11th to 20th	Night	12% 13% 5% 8% 6% 3 5% 6% 6% 6% 29%	2660
	21st to end	Night	12% 16% 6% 11% 7% 3 5% 4 5% 6% 25%	2723
December	1st to 10th	Night	9% 14% 6% 10% 8% 4 5% 5% 6% 6% 28%	2850
	11th to 20th	Night	12% 20% 7% 12% 8% 4 5% 4 5% 5% 17%	3510
	21st to end	Night	12% 18% 7% 12% 8% 4 6% 4 4 5% 18%	5342

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	64% 7% 15% 11% 3	2321
	11th to 20th	Day	56% 8% 18% 11% 2 5%	2540
	21st to end	Day	65% 7% 15% 10% 2	2794
February	1st to 10th	Day	59% 8% 13% 14% 6% 1	1572
	11th to 20th	Day	49% 11% 18% 16% 6%	1621
	21st to end	Day	58% 8% 15% 14% 5%	1453
March	1st to 10th	Day	49% 10% 18% 15% 8% 1	1800
	11th to 20th	Day	51% 8% 17% 18% 6%	1891
	21st to end	Day	54% 7% 20% 13% 5% 1	2340
April	1st to 10th	Day	52% 8% 15% 17% 7% 1	2160
	11th to 20th	Day	48% 8% 14% 18% 9% 2	2138
	21st to end	Day	46% 7% 16% 19% 11% 1	2474
May	1st to 10th	Day	44% 6% 17% 21% 11% 1	2520
	11th to 20th	Day	43% 7% 18% 23% 8% 1	2480
	21st to end	Day	48% 7% 16% 22% 7% 1	2724
June	1st to 10th	Day	51% 5% 14% 16% 10% 4	2713
	11th to 20th	Day	49% 7% 16% 19% 9% 1	2880
	21st to end	Day	39% 6% 18% 21% 13% 3	2880
July	1st to 10th	Day	33% 6% 13% 24% 18% 6%	2632
	11th to 20th	Day	27% 6% 13% 27% 22% 6%	2488
	21st to end	Day	18% 5% 12% 27% 30% 8%	2589
August	1st to 10th	Day	23% 5% 16% 28% 22% 7%	2490
	11th to 20th	Day	23% 5% 15% 29% 22% 5%	2453
	21st to end	Day	31% 5% 17% 31% 15% 2	2413
September	1st to 10th	Day	29% 5% 17% 28% 19% 3	2160
	11th to 20th	Day	36% 6% 16% 22% 18% 3	2151
	21st to end	Day	37% 7% 22% 21% 12% 1	1952
October	1st to 10th	Day	40% 5% 18% 30% 7%	1800
	11th to 20th	Day	44% 7% 19% 23% 7%	1757
	21st to end	Day	49% 8% 17% 21% 4	1782
November	1st to 10th	Day	53% 10% 16% 16% 5%	1575
	11th to 20th	Day	55% 11% 15% 13% 5% 1	1520
	21st to end	Day	56% 9% 16% 13% 6%	1435
December	1st to 10th	Day	57% 8% 16% 16% 2	1330
	11th to 20th	Day	60% 9% 18% 10% 4	1684
	21st to end	Day	61% 9% 15% 13% 3	2319
January	1st to 10th	Night	67% 7% 13% 10% 4	4618
	11th to 20th	Night	56% 8% 17% 12% 4 3	4420
	21st to end	Night	67% 7% 13% 9% 3	4862
February	1st to 10th	Night	60% 6% 15% 12% 7%	2605
	11th to 20th	Night	48% 7% 17% 20% 8%	2331
	21st to end	Night	53% 8% 16% 16% 8%	1803
March	1st to 10th	Night	49% 8% 18% 14% 9% 1	2160
	11th to 20th	Night	43% 9% 17% 23% 8%	2066
	21st to end	Night	49% 8% 19% 19% 5%	2016
April	1st to 10th	Night	43% 8% 21% 22% 7% 1	1800
	11th to 20th	Night	42% 7% 19% 20% 11% 1	1772
	21st to end	Night	43% 6% 18% 23% 10%	1483
May	1st to 10th	Night	37% 7% 18% 24% 12% 1	1440
	11th to 20th	Night	36% 8% 24% 23% 9%	1416
	21st to end	Night	41% 6% 20% 25% 8% 1	1552
June	1st to 10th	Night	41% 9% 15% 23% 9% 4	1238
	11th to 20th	Night	37% 5% 22% 27% 9%	1080
	21st to end	Night	29% 6% 23% 26% 13% 3	1080
July	1st to 10th	Night	25% 4 16% 29% 19% 6%	1215
	11th to 20th	Night	19% 7% 16% 31% 24% 4	1345
	21st to end	Night	13% 3 14% 31% 30% 10%	1488
August	1st to 10th	Night	17% 5% 15% 30% 24% 9%	1424
	11th to 20th	Night	17% 4 16% 34% 24% 5%	1444
	21st to end	Night	23% 5% 18% 34% 17% 3	1942
September	1st to 10th	Night	24% 3 18% 31% 19% 4	1800
	11th to 20th	Night	27% 6% 16% 25% 21% 4	1808
	21st to end	Night	34% 6% 21% 25% 11% 3	2006
October	1st to 10th	Night	36% 6% 19% 29% 9% 1	2160
	11th to 20th	Night	42% 7% 16% 25% 10%	2202
	21st to end	Night	45% 8% 17% 24% 7%	2574
November	1st to 10th	Night	52% 9% 17% 16% 6%	2501
	11th to 20th	Night	53% 10% 15% 14% 7% 1	2660
	21st to end	Night	58% 7% 17% 12% 5%	2723
December	1st to 10th	Night	58% 8% 14% 17% 4	2850
	11th to 20th	Night	66% 9% 14% 8% 3	3507
	21st to end	Night	65% 7% 14% 10% 4	5342

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% 17% 27% 19% 12% 6%	180
	11th to 20th	Day	21% 14% 26% 23% 13% 2	180
	21st to end	Day	21% 14% 31% 22% 10% 2	198
February	1st to 10th	Day	14% 23% 38% 19% 6% 1	232
	11th to 20th	Day	17% 19% 36% 23% 4 1	348
	21st to end	Day	12% 21% 33% 24% 10%	334
March	1st to 10th	Day	15% 25% 32% 20% 7% 1	420
	11th to 20th	Day	16% 24% 29% 20% 9% 2	420
	21st to end	Day	18% 25% 29% 18% 9% 1	462
April	1st to 10th	Day	22% 22% 30% 17% 8% 1	420
	11th to 20th	Day	17% 27% 25% 18% 10% 2	412
	21st to end	Day	15% 22% 31% 20% 9% 4	420
May	1st to 10th	Day	15% 18% 34% 23% 9% 2	423
	11th to 20th	Day	16% 15% 24% 25% 18% 3	448
	21st to end	Day	14% 14% 26% 28% 14% 3	485
June	1st to 10th	Day	18% 16% 30% 24% 11% 1	643
	11th to 20th	Day	16% 19% 30% 22% 10% 3	810
	21st to end	Day	9% 13% 29% 28% 17% 3	810
July	1st to 10th	Day	8% 14% 31% 31% 16% 1	627
	11th to 20th	Day	7% 17% 25% 32% 16% 4	487
	21st to end	Day	5% 11% 26% 35% 18% 4	487
August	1st to 10th	Day	5% 9% 28% 34% 19% 5%	447
	11th to 20th	Day	6% 10% 29% 31% 19% 5%	437
	21st to end	Day	8% 17% 24% 31% 14% 5%	495
September	1st to 10th	Day	9% 17% 31% 27% 11% 6%	450
	11th to 20th	Day	12% 16% 25% 26% 17% 4	450
	21st to end	Day	17% 15% 31% 23% 12% 2	450
October	1st to 10th	Day	13% 16% 30% 22% 14% 4	450
	11th to 20th	Day	16% 22% 23% 23% 13% 2	407
	21st to end	Day	23% 15% 31% 21% 7% 2	297
November	1st to 10th	Day	16% 21% 35% 21% 7%	223
	11th to 20th	Day	18% 25% 28% 16% 10% 3	180
	21st to end	Day	18% 17% 27% 24% 10% 4	180
December	1st to 10th	Day	14% 16% 24% 23% 18% 5%	180
	11th to 20th	Day	12% 20% 34% 22% 7% 4	180
	21st to end	Day	13% 13% 33% 26% 13% 2	198
January	1st to 10th	Night	23% 13% 29% 24% 10% 1	817
	11th to 20th	Night	18% 10% 31% 27% 12% 1	760
	21st to end	Night	16% 10% 29% 30% 12% 3	836
February	1st to 10th	Night	20% 13% 28% 28% 9% 2	760
	11th to 20th	Night	14% 11% 31% 30% 13% 2	722
	21st to end	Night	14% 13% 23% 32% 17% 2	592
March	1st to 10th	Night	13% 12% 28% 28% 17% 3	720
	11th to 20th	Night	12% 13% 31% 28% 14% 2	720
	21st to end	Night	13% 11% 29% 31% 14% 2	792
April	1st to 10th	Night	12% 12% 26% 32% 15% 2	720
	11th to 20th	Night	10% 14% 29% 29% 16% 1	704
	21st to end	Night	10% 13% 34% 29% 13% 1	403
May	1st to 10th	Night	10% 11% 27% 35% 15% 2	360
	11th to 20th	Night	10% 6% 22% 37% 23% 1	354
	21st to end	Night	14% 8% 23% 32% 21% 2	389
June	1st to 10th	Night	12% 10% 33% 30% 13% 1	360
	11th to 20th	Night	10% 11% 35% 28% 14% 1	360
	21st to end	Night	6% 10% 30% 33% 18% 3	360
July	1st to 10th	Night	5% 9% 24% 40% 21% 1	350
	11th to 20th	Night	2 13% 28% 36% 20% 1	348
	21st to end	Night	4 8% 23% 38% 24% 3	394
August	1st to 10th	Night	3 5% 21% 38% 28% 4	358
	11th to 20th	Night	5% 3 21% 35% 31% 5%	376
	21st to end	Night	5% 7% 24% 35% 25% 3	754
September	1st to 10th	Night	6% 9% 25% 32% 25% 4	720
	11th to 20th	Night	9% 7% 20% 25% 28% 10%	720
	21st to end	Night	11% 8% 23% 33% 21% 3	720
October	1st to 10th	Night	14% 7% 19% 33% 22% 4	720
	11th to 20th	Night	15% 12% 23% 30% 17% 3	720
	21st to end	Night	20% 13% 26% 26% 13% 3	792
November	1st to 10th	Night	21% 9% 31% 30% 8% 1	740
	11th to 20th	Night	19% 15% 26% 26% 11% 2	760
	21st to end	Night	18% 12% 29% 27% 10% 3	823
December	1st to 10th	Night	16% 10% 29% 29% 13% 2	950
	11th to 20th	Night	21% 10% 32% 27% 8% 1	950
	21st to end	Night	19% 10% 30% 30% 10% 1	1043

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