Parc de la Frayère Clear Sky Chart History

Parc de la Frayère
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Parc de la Frayère clear sky chart from 2005-11-05 to 2017-12-20.

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

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

Planetary

Data
Pts

Deep Sky
Max 60%

Data
Pts

Both Planetary and Deep Sky
Max 60%

Data
Pts

Either Planetary or Deep Sky

Data
Pts

CCD Imaging

Data
Pts

Night

33%

15001

13%

48041

14970

38%

14970

17%

34595

By Month

Month

Days of Month

Planetary

Data
Pts

Deep Sky
Max 60%

Data
Pts

Both Planetary and Deep Sky
Max 60%

Data
Pts

Either Planetary or Deep Sky

Data
Pts

CCD Imaging

Data
Pts

January

1st to 15th

Night

22%

720

2506

716

26%

716

1975

January

16th to end

Night

24%

768

10%

2688

768

30%

768

11%

2030

February

1st to 15th

Night

21%

703

2315

701

27%

701

10%

1840

February

16th to end

Night

26%

631

12%

1893

631

33%

631

14%

1446

March

1st to 15th

Night

28%

720

13%

2160

720

34%

720

15%

1642

March

16th to end

Night

34%

768

18%

2000

10%

768

39%

768

23%

1435

April

1st to 15th

Night

27%

718

15%

1796

718

33%

718

19%

1368

April

16th to end

Night

29%

612

16%

1692

612

37%

612

21%

1199

May

1st to 15th

Night

32%

402

16%

1482

14%

402

41%

402

17%

1002

May

16th to end

Night

33%

375

12%

1497

11%

374

41%

374

17%

988

June

1st to 15th

Night

37%

360

1440

360

43%

360

13%

1014

June

16th to end

Night

45%

360

1440

11%

360

49%

360

17%

942

July

1st to 15th

Night

53%

340

11%

1360

17%

340

58%

340

23%

809

July

16th to end

Night

55%

376

12%

1418

16%

354

58%

354

23%

851

August

1st to 15th

Night

55%

368

14%

1439

16%

366

58%

366

20%

912

August

16th to end

Night

56%

747

18%

1893

11%

747

58%

747

34%

1240

September

1st to 15th

Night

49%

720

14%

1800

720

50%

720

28%

1260

September

16th to end

Night

50%

717

22%

1977

15%

717

54%

717

31%

1252

October

1st to 15th

Night

35%

720

18%

2109

11%

720

44%

720

22%

1450

October

16th to end

Night

28%

768

12%

2472

768

34%

768

15%

1820

November

1st to 15th

Night

26%

760

17%

2472

12%

760

34%

760

16%

1757

November

16th to end

Night

24%

780

13%

2707

780

31%

780

12%

2024

December

1st to 15th

Night

18%

780

2730

780

24%

780

2146

December

16th to end

Night

15%

788

10%

2755

788

24%

788

2193

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
18% 8% 3 6% 5% 3 4 4 5% 6% 33%
48804
Night
19% 9% 4 6% 5% 3 4 4 4 6% 32%
48210
Cloud Cover Day
18% 8% 3 6% 5% 3 4 4 5% 6% 33%
48814
Night
19% 9% 4 6% 5% 3 4 4 4 6% 32%
48215
Transparency Day
50% 6% 12% 19% 9% 1
48491
Night
53% 5% 10% 18% 9% 1
48041
Seeing Day
22% 6% 25% 26% 14% 4
5866
Night
23% 6% 28% 29% 10%
15002

By Month

Percentage Cloud Cover NE (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 15th Day
22% 13% 5% 8% 8% 4 4 3 3 4 21%
1432
16th to end Day
14% 13% 3 8% 6% 3 5% 5% 4 6% 28%
1536
February 1st to 15th Day
14% 14% 5% 10% 6% 3 5% 4 4 5% 24%
1543
16th to end Day
17% 12% 5% 7% 7% 2 4 4 5% 4 28%
1580
March 1st to 15th Day
17% 10% 4 7% 6% 4 5% 4 4 5% 28%
1790
16th to end Day
18% 8% 4 5% 4 3 4 3 3 5% 37%
2223
April 1st to 15th Day
22% 9% 2 7% 5% 3 4 3 3 5% 32%
2152
16th to end Day
19% 7% 2 6% 4 2 4 4 4 5% 38%
2267
May 1st to 15th Day
21% 6% 3 5% 5% 3 4 5% 5% 5% 33%
2478
16th to end Day
20% 5% 3 5% 5% 3 4 5% 5% 7% 34%
2618
June 1st to 15th Day
23% 5% 2 4 5% 3 4 5% 5% 8% 31%
2520
16th to end Day
17% 6% 2 5% 5% 3 5% 4 6% 8% 31%
2520
July 1st to 15th Day
12% 4 2 5% 5% 3 6% 5% 6% 9% 37%
2520
16th to end Day
12% 4 2 5% 5% 3 5% 5% 8% 9% 36%
2654
August 1st to 15th Day
12% 5% 2 6% 7% 3 5% 5% 5% 9% 34%
2497
16th to end Day
9% 4 2 4 4 3 4 5% 6% 7% 47%
2308
September 1st to 15th Day
16% 5% 2 5% 3 2 4 4 5% 7% 43%
2160
16th to end Day
13% 4 1 4 4 2 3 3 4 6% 49%
1983
October 1st to 15th Day
19% 6% 3 6% 5% 3 4 4 4 7% 34%
1848
16th to end Day
23% 8% 3 6% 6% 3 4 4 4 4 29%
1752
November 1st to 15th Day
17% 9% 3 5% 5% 3 4 5% 5% 6% 31%
1716
16th to end Day
22% 9% 3 7% 5% 2 5% 4 3 4 30%
1579
December 1st to 15th Day
25% 11% 5% 7% 5% 3 4 4 5% 5% 21%
1560
16th to end Day
26% 15% 4 6% 5% 2 3 3 3 6% 21%
1568
January 1st to 15th Night
18% 15% 6% 9% 6% 3 4 4 4 5% 22%
2506
16th to end Night
13% 13% 6% 7% 7% 3 5% 4 5% 5% 25%
2688
February 1st to 15th Night
14% 12% 7% 11% 7% 4 6% 3 4 4 22%
2313
16th to end Night
17% 12% 5% 8% 6% 4 4 4 4 4 28%
1893
March 1st to 15th Night
21% 11% 4 6% 5% 3 4 3 4 4 29%
2147
16th to end Night
17% 10% 3 5% 5% 2 4 3 3 5% 38%
2000
April 1st to 15th Night
26% 8% 4 5% 5% 2 3 3 3 5% 31%
1796
16th to end Night
23% 7% 2 5% 5% 2 3 3 4 5% 36%
1692
May 1st to 15th Night
20% 7% 3 6% 5% 2 4 4 4 5% 36%
1482
16th to end Night
21% 6% 2 5% 5% 2 4 4 5% 7% 34%
1495
June 1st to 15th Night
26% 6% 3 5% 4 2 4 4 6% 6% 29%
1440
16th to end Night
16% 5% 2 6% 4 3 4 5% 6% 8% 35%
1440
July 1st to 15th Night
11% 4 2 5% 4 4 6% 4 6% 11% 39%
1440
16th to end Night
11% 3 3 4 4 3 4 6% 6% 9% 41%
1514
August 1st to 15th Night
12% 5% 2 6% 5% 3 4 5% 6% 8% 38%
1449
16th to end Night
12% 4 1 4 4 2 4 4 5% 8% 45%
1893
September 1st to 15th Night
16% 5% 2 5% 5% 2 3 5% 4 6% 41%
1800
16th to end Night
17% 4 2 3 3 2 2 3 4 7% 48%
1977
October 1st to 15th Night
17% 6% 2 6% 5% 2 4 4 4 6% 39%
2109
16th to end Night
25% 8% 3 6% 5% 3 3 3 4 5% 31%
2472
November 1st to 15th Night
21% 8% 2 6% 5% 3 4 4 4 5% 33%
2472
16th to end Night
23% 12% 4 7% 5% 3 4 3 3 4 28%
2707
December 1st to 15th Night
23% 13% 5% 8% 6% 2 3 3 3 5% 23%
2730
16th to end Night
24% 16% 5% 8% 5% 2 3 3 3 4 22%
2755

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 15th Day
22% 14% 5% 8% 7% 3 4 4 3 3 22%
1432
16th to end Day
14% 13% 4 7% 6% 3 5% 4 4 5% 28%
1536
February 1st to 15th Day
14% 14% 5% 9% 6% 4 6% 4 3 5% 23%
1543
16th to end Day
18% 13% 5% 8% 6% 3 3 3 5% 4 27%
1580
March 1st to 15th Day
18% 10% 4 8% 6% 3 4 5% 3 5% 27%
1800
16th to end Day
17% 8% 4 7% 5% 2 3 4 4 5% 36%
2223
April 1st to 15th Day
23% 9% 3 6% 5% 3 4 3 3 4 32%
2152
16th to end Day
20% 7% 3 5% 5% 3 4 3 4 5% 38%
2267
May 1st to 15th Day
20% 6% 3 5% 6% 3 4 3 5% 7% 32%
2478
16th to end Day
20% 6% 2 6% 5% 3 4 4 5% 8% 33%
2618
June 1st to 15th Day
22% 6% 2 5% 4 3 4 4 5% 7% 31%
2520
16th to end Day
17% 6% 3 6% 4 3 5% 5% 6% 8% 31%
2520
July 1st to 15th Day
12% 4 3 6% 4 4 5% 6% 6% 8% 37%
2520
16th to end Day
12% 4 2 5% 5% 3 6% 5% 7% 9% 36%
2654
August 1st to 15th Day
13% 5% 2 6% 6% 4 5% 5% 6% 8% 34%
2497
16th to end Day
9% 4 1 3 4 3 4 5% 6% 8% 46%
2308
September 1st to 15th Day
15% 5% 2 5% 4 2 3 4 4 8% 42%
2160
16th to end Day
13% 4 1 3 4 3 3 3 4 6% 49%
1983
October 1st to 15th Day
19% 6% 3 6% 5% 3 4 4 4 6% 34%
1848
16th to end Day
23% 9% 3 6% 6% 3 4 4 4 5% 29%
1752
November 1st to 15th Day
17% 10% 3 5% 5% 3 5% 4 6% 6% 31%
1716
16th to end Day
23% 9% 4 6% 5% 3 4 5% 4 4 29%
1579
December 1st to 15th Day
25% 12% 5% 8% 5% 2 4 3 5% 5% 21%
1560
16th to end Day
26% 15% 5% 6% 4 2 4 3 3 4 22%
1568
January 1st to 15th Night
19% 15% 5% 9% 6% 2 4 4 4 5% 21%
2506
16th to end Night
13% 13% 6% 8% 6% 4 5% 5% 5% 5% 25%
2688
February 1st to 15th Night
14% 13% 7% 11% 8% 3 6% 4 4 4 22%
2306
16th to end Night
17% 12% 5% 8% 6% 3 5% 4 4 4 27%
1893
March 1st to 15th Night
21% 12% 4 6% 6% 2 4 3 4 4 29%
2160
16th to end Night
17% 10% 3 6% 4 2 4 3 3 4 38%
1999
April 1st to 15th Night
26% 8% 4 4 5% 2 4 3 3 5% 30%
1796
16th to end Night
23% 7% 2 5% 4 2 4 3 4 5% 35%
1692
May 1st to 15th Night
20% 7% 3 6% 5% 3 3 3 5% 5% 35%
1482
16th to end Night
20% 7% 2 6% 4 2 4 4 4 8% 33%
1495
June 1st to 15th Night
25% 7% 3 5% 3 3 4 4 5% 7% 28%
1440
16th to end Night
16% 5% 3 6% 4 2 5% 5% 6% 8% 35%
1440
July 1st to 15th Night
11% 4 1 5% 5% 3 5% 5% 6% 10% 39%
1440
16th to end Night
11% 4 1 5% 5% 3 6% 5% 7% 9% 40%
1514
August 1st to 15th Night
13% 6% 2 5% 5% 3 5% 5% 6% 8% 37%
1449
16th to end Night
12% 4 2 5% 4 3 3 4 5% 8% 45%
1893
September 1st to 15th Night
16% 5% 2 5% 5% 2 4 5% 4 5% 41%
1800
16th to end Night
17% 4 2 3 2 2 3 2 4 7% 48%
1977
October 1st to 15th Night
18% 6% 3 5% 4 2 4 4 4 5% 39%
2109
16th to end Night
26% 8% 3 6% 4 3 3 3 4 5% 31%
2472
November 1st to 15th Night
22% 8% 2 6% 5% 3 4 4 4 5% 32%
2472
16th to end Night
24% 11% 4 7% 4 3 4 3 3 4 28%
2707
December 1st to 15th Night
23% 13% 5% 8% 6% 2 4 3 3 5% 22%
2730
16th to end Night
23% 16% 6% 8% 5% 2 3 3 3 4 22%
2755

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 15th Day
67% 5% 9% 12% 5%
1433
16th to end Day
57% 6% 12% 15% 7%
1536
February 1st to 15th Day
62% 4 10% 17% 4
1545
16th to end Day
59% 4 9% 15% 9% 1
1580
March 1st to 15th Day
58% 5% 10% 16% 8% 1
1800
16th to end Day
48% 4 10% 18% 13% 3
2223
April 1st to 15th Day
55% 4 7% 19% 11% 2
2152
16th to end Day
49% 4 9% 19% 13% 3
2267
May 1st to 15th Day
51% 5% 10% 18% 12% 1
2478
16th to end Day
48% 6% 12% 18% 11% 1
2622
June 1st to 15th Day
50% 7% 11% 18% 10% 1
2520
16th to end Day
49% 7% 11% 22% 7% 1
2520
July 1st to 15th Day
40% 8% 14% 25% 11%
2371
16th to end Day
41% 8% 19% 22% 7%
2487
August 1st to 15th Day
45% 8% 17% 21% 6%
2483
16th to end Day
32% 8% 18% 27% 12%
2308
September 1st to 15th Day
40% 6% 15% 26% 11%
2160
16th to end Day
35% 5% 13% 32% 13%
1983
October 1st to 15th Day
50% 6% 12% 22% 8%
1848
16th to end Day
57% 5% 13% 16% 6%
1752
November 1st to 15th Day
51% 6% 13% 18% 8%
1716
16th to end Day
55% 7% 11% 15% 8%
1579
December 1st to 15th Day
64% 6% 12% 12% 4
1560
16th to end Day
66% 6% 10% 9% 7%
1568
January 1st to 15th Night
64% 5% 10% 14% 4
2506
16th to end Night
59% 6% 10% 15% 7%
2688
February 1st to 15th Night
64% 5% 9% 14% 5%
2315
16th to end Night
59% 5% 10% 14% 10%
1893
March 1st to 15th Night
58% 5% 8% 16% 9% 1
2160
16th to end Night
50% 4 9% 17% 15% 3
2000
April 1st to 15th Night
57% 3 5% 18% 14% 1
1796
16th to end Night
50% 4 8% 18% 14% 4
1692
May 1st to 15th Night
51% 4 8% 17% 13% 4
1482
16th to end Night
49% 5% 10% 20% 12% 2
1497
June 1st to 15th Night
54% 6% 9% 18% 10%
1440
16th to end Night
44% 9% 11% 19% 14% 1
1440
July 1st to 15th Night
37% 7% 14% 25% 13%
1360
16th to end Night
37% 8% 17% 22% 13%
1418
August 1st to 15th Night
42% 8% 16% 22% 10%
1439
16th to end Night
36% 6% 16% 28% 11%
1893
September 1st to 15th Night
42% 6% 11% 24% 13%
1800
16th to end Night
36% 6% 11% 30% 14%
1977
October 1st to 15th Night
46% 6% 10% 25% 11%
2109
16th to end Night
55% 5% 11% 19% 7%
2472
November 1st to 15th Night
53% 4 12% 19% 8% 1
2472
16th to end Night
59% 4 10% 17% 6%
2707
December 1st to 15th Night
64% 5% 11% 14% 4
2730
16th to end Night
66% 4 9% 11% 6%
2755

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 15th Day
21% 11% 21% 30% 15%
60
16th to end Day
34% 6% 32% 15% 9% 1
64
February 1st to 15th Day
29% 10% 31% 24% 3
91
16th to end Day
27% 8% 26% 29% 6%
239
March 1st to 15th Day
25% 8% 29% 27% 8%
270
16th to end Day
23% 3 30% 27% 12% 2
288
April 1st to 15th Day
27% 11% 28% 19% 10% 2
270
16th to end Day
22% 10% 27% 24% 12% 3
270
May 1st to 15th Day
27% 6% 29% 18% 14% 4
288
16th to end Day
23% 7% 29% 21% 15% 2
331
June 1st to 15th Day
26% 8% 20% 30% 11% 2
315
16th to end Day
18% 7% 24% 30% 16% 2
315
July 1st to 15th Day
15% 4 24% 29% 19% 6%
305
16th to end Day
15% 2 17% 36% 22% 5%
326
August 1st to 15th Day
15% 3 19% 30% 23% 8%
313
16th to end Day
10% 4 20% 28% 20% 15%
332
September 1st to 15th Day
16% 3 20% 27% 19% 12%
315
16th to end Day
14% 5% 25% 21% 21% 11%
314
October 1st to 15th Day
22% 7% 24% 26% 14% 3
315
16th to end Day
28% 8% 26% 23% 11%
294
November 1st to 15th Day
23% 7% 30% 21% 14% 1
280
16th to end Day
31% 11% 24% 23% 7%
109
December 1st to 15th Day
26% 8% 27% 23% 10% 3
90
16th to end Day
41% 15% 29% 13%
72
January 1st to 15th Night
25% 11% 30% 26% 6%
720
16th to end Night
21% 8% 33% 28% 7% 1
768
February 1st to 15th Night
20% 7% 34% 28% 7%
704
16th to end Night
22% 6% 33% 30% 6%
631
March 1st to 15th Night
28% 6% 28% 29% 6%
720
16th to end Night
21% 4 31% 31% 9%
768
April 1st to 15th Night
29% 10% 25% 29% 5%
718
16th to end Night
26% 9% 28% 25% 8%
612
May 1st to 15th Night
24% 5% 30% 28% 10%
402
16th to end Night
22% 6% 30% 31% 7%
375
June 1st to 15th Night
27% 4 21% 34% 11%
360
16th to end Night
17% 3 28% 37% 12%
360
July 1st to 15th Night
11% 3 26% 38% 19%
340
16th to end Night
13% 1 21% 45% 17%
376
August 1st to 15th Night
13% 2 16% 42% 22% 2
368
16th to end Night
14% 2 19% 38% 23% 2
747
September 1st to 15th Night
20% 3 19% 40% 15% 1
720
16th to end Night
17% 4 22% 31% 19% 3
717
October 1st to 15th Night
21% 5% 30% 28% 12% 1
720
16th to end Night
30% 8% 27% 24% 8%
768
November 1st to 15th Night
26% 7% 30% 24% 10%
760
16th to end Night
29% 9% 29% 20% 10%
780
December 1st to 15th Night
29% 8% 31% 24% 5%
780
16th to end Night
31% 7% 31% 21% 6% 1
788
Page generated at 2017-12-21 07:04:53. Version ac04

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