The Vapour Pressure of Water

It is sometimes useful to know the vapour pressure of water. Below is a list of high-precision values. This uses the Wagner & Pruss equation (1993 J Phys Chem Ref Data 22, pp 783-787).

The table uses the modern single-fixed-point thermodynamic temperature scale in which the triple point of water is 273.16 K exactly, and celsius degrees are defined as K - 273.15. The boiling point of water is no longer a fixed point. Referring to the table, the "normal boiling point" (i.e. at 1 standard atmosphere pressure = 101325 Pa) is 99.9743°C, while the IUPAC standard boiling point (i.e. at 100 kPa) is 99.6059°C.

temp °Cpressure kPa
0 0.61121
1 0.65708
2 0.70597
3 0.75805
4 0.81351
5 0.87253
6 0.93530
7 1.00203
8 1.07292
9 1.14821
10 1.22811
11 1.31288
12 1.40275
13 1.49799
14 1.59887
15 1.70568
16 1.81870
17 1.93824
18 2.06461
19 2.19815
20 2.33919
21 2.48810
22 2.64522
23 2.81096
24 2.98569
25 3.16982
26 3.36379
27 3.56802
28 3.78298
29 4.00911
30 4.24692
31 4.49690
32 4.75956
33 5.03543
34 5.32508
35 5.62906
36 5.94796
37 6.28238
38 6.63295
39 7.00031
40 7.38511
41 7.78804
42 8.20980
43 8.65110
44 9.11270
45 9.59534
46 10.09981
47 10.62693
48 11.17751
49 11.75240
50 12.35248
51 12.97864
52 13.63180
53 14.31291
54 15.02293
55 15.76284
56 16.53368
57 17.33647
58 18.17228
59 19.04222
60 19.94738
61 20.88893
62 21.86802
63 22.88587
64 23.94368
65 25.04273
66 26.18428
67 27.36965
68 28.60018
69 29.87723
70 31.20220
71 32.57651
72 34.00162
73 35.47901
74 37.01020
75 38.59673
76 40.24018
77 41.94216
78 43.70430
79 45.52827
80 47.41578
81 49.36856
82 51.38837
83 53.47701
84 55.63632
85 57.86815
86 60.17439
87 62.55699
88 65.01790
89 67.55912
90 70.18268
91 72.89064
92 75.68510
93 78.56819
94 81.54209
95 84.60899
96 87.77112
97 91.03076
98 94.39022
99 97.85184
100 101.4180
101 105.0911
102 108.8736
103 112.7680
104 116.7767
105 120.9025
106 125.1477
107 129.5152
108 134.0074
109 138.6273
110 143.3773
111 148.2605
112 153.2795
113 158.4372
114 163.7364
115 169.1802
116 174.7714
117 180.5131
118 186.4083
119 192.4600
120 198.6714
121 205.0456
122 211.5857
123 218.2951
124 225.1769
125 232.2344
126 239.4709
127 246.8899
128 254.4947
129 262.2887
130 270.2754
131 278.4584
132 286.8412
133 295.4274
134 304.2205
135 313.2243
136 322.4424
137 331.8786
138 341.5366
139 351.4203
140 361.5335
141 371.8801
142 382.4639
143 393.2890
144 404.3593
145 415.6788
146 427.2517
147 439.0819
148 451.1738
149 463.5313
150 476.1587
151 489.0603
152 502.2404
153 515.7032
154 529.4531
155 543.4945
156 557.8318
157 572.4694
158 587.4120
159 602.6639
160 618.2297
161 634.1141
162 650.3217
163 666.8572
164 683.7251
165 700.9304
166 718.4777
167 736.3720
168 754.6179
169 773.2204
170 792.1844
171 811.5148
172 831.2167
173 851.2950
174 871.7547
175 892.6011
176 913.8391
177 935.4739
178 957.5108
179 979.9549
180 1002.811
181 1026.086
182 1049.783
183 1073.909
184 1098.469
185 1123.467
186 1148.911
187 1174.805
188 1201.154
189 1227.964
190 1255.242
191 1282.992
192 1311.219
193 1339.931
194 1369.132
195 1398.828
196 1429.025
197 1459.729
198 1490.945
199 1522.680
200 1554.939
201 1587.729
202 1621.055
203 1654.923
204 1689.339
205 1724.310
206 1759.841
207 1795.938
208 1832.609
209 1869.858
210 1907.692
211 1946.118
212 1985.142
213 2024.769
214 2065.007
215 2105.861
216 2147.339
217 2189.446
218 2232.189
219 2275.575
220 2319.610
221 2364.300
222 2409.652
223 2455.674
224 2502.371
225 2549.750
226 2597.818
227 2646.582
228 2696.048
229 2746.224
230 2797.116
231 2848.730
232 2901.075
233 2954.157
234 3007.983
235 3062.560
236 3117.894
237 3173.994
238 3230.866
239 3288.518
240 3346.956
241 3406.188
242 3466.220
243 3527.062
244 3588.719
245 3651.199
246 3714.509
247 3778.657
248 3843.651
249 3909.497
250 3976.204
251 4043.779
252 4112.230
253 4181.564
254 4251.789
255 4322.912
256 4394.942
257 4467.886
258 4541.753
259 4616.550
260 4692.284
261 4768.965
262 4846.599
263 4925.196
264 5004.763
265 5085.308
266 5166.840
267 5249.367
268 5332.896
269 5417.437
270 5502.998
271 5589.587
272 5677.213
273 5765.884
274 5855.609
275 5946.397
276 6038.256
277 6131.194
278 6225.222
279 6320.346
280 6416.578
281 6513.925
282 6612.396
283 6712.001
284 6812.749
285 6914.649
286 7017.710
287 7121.941
288 7227.353
289 7333.954
290 7441.755
291 7550.764
292 7660.991
293 7772.447
294 7885.141
295 7999.083
296 8114.283
297 8230.751
298 8348.498
299 8467.533
300 8587.867
301 8709.511
302 8832.475
303 8956.770
304 9082.406
305 9209.395
306 9337.747
307 9467.474
308 9598.586
309 9731.096
310 9865.014
311 10000.35
312 10137.12
313 10275.34
314 10415.00
315 10556.14
316 10698.76
317 10842.87
318 10988.48
319 11135.62
320 11284.28
321 11434.49
322 11586.25
323 11739.58
324 11894.50
325 12051.02
326 12209.15
327 12368.90
328 12530.30
329 12693.35
330 12858.08
331 13024.49
332 13192.60
333 13362.43
334 13533.99
335 13707.30
336 13882.38
337 14059.24
338 14237.91
339 14418.39
340 14600.71
341 14784.89
342 14970.94
343 15158.89
344 15348.75
345 15540.55
346 15734.31
347 15930.04
348 16127.77
349 16327.53
350 16529.34
351 16733.22
352 16939.20
353 17147.30
354 17357.56
355 17569.99
356 17784.64
357 18001.53
358 18220.70
359 18442.17
360 18666.00
361 18892.21
362 19120.85
363 19351.96
364 19585.59
365 19821.79
366 20060.64
367 20302.18
368 20546.49
369 20793.67
370 21043.82
371 21297.08
372 21553.65
373 21813.82

NOTES

Note 1.