20 (日)	02:46	09:11	15:36	21:19
	117cm	20cm	115cm	49cm
大潮 出 04:59 入 18:17 出 03:48 入 16:54 潮干狩り ○ 07:36～10:43

日立（茨城）2031年04月20日の10分毎の潮の高低差を確認できます。
また1日の潮の高低差が1番大きい（潮の流れが大きい）時間に「最大潮位差」と明記してます。

時刻	潮位	高低差	各ポイント
4/20 00:00	85.6	↑3.1
4/20 00:10	88.7	↑3.1
4/20 00:20	91.7	↑3.0
4/20 00:30	94.6	↑2.9
4/20 00:40	97.4	↑2.8
4/20 00:50	100.1	↑2.7
4/20 01:00	102.6	↑2.5
4/20 01:10	104.9	↑2.3
4/20 01:20	107.1	↑2.2
4/20 01:30	109.1	↑2.0
4/20 01:40	110.8	↑1.7
4/20 01:50	112.4	↑1.6
4/20 02:00	113.7	↑1.3
4/20 02:10	114.7	↑1.0
4/20 02:20	115.6	↑0.9
4/20 02:30	116.1	↑0.5
4/20 02:40	116.4	↑0.3	満潮
4/20 02:50	116.4	0
4/20 03:00	116.1	↓-0.3
4/20 03:10	115.5	↓-0.6
4/20 03:20	114.6	↓-0.9
4/20 03:30	113.4	↓-1.2
4/20 03:40	111.9	↓-1.5
4/20 03:50	110.1	↓-1.8
4/20 04:00	108.0	↓-2.1
4/20 04:10	105.7	↓-2.3
4/20 04:20	103.0	↓-2.7
4/20 04:30	100.1	↓-2.9
4/20 04:40	97.0	↓-3.1
4/20 04:50	93.7	↓-3.3
4/20 05:00	90.2	↓-3.5
4/20 05:10	86.5	↓-3.7
4/20 05:20	82.7	↓-3.8
4/20 05:30	78.8	↓-3.9
4/20 05:40	74.8	↓-4.0	最大潮位差
4/20 05:50	70.8	↓-4.0	最大潮位差
4/20 06:00	66.8	↓-4.0	最大潮位差
4/20 06:10	62.8	↓-4.0	最大潮位差
4/20 06:20	58.8	↓-4.0	最大潮位差
4/20 06:30	54.9	↓-3.9
4/20 06:40	51.1	↓-3.8
4/20 06:50	47.4	↓-3.7
4/20 07:00	43.9	↓-3.5
4/20 07:10	40.6	↓-3.3
4/20 07:20	37.4	↓-3.2
4/20 07:30	34.4	↓-3.0
4/20 07:40	31.7	↓-2.7
4/20 07:50	29.2	↓-2.5
4/20 08:00	27.0	↓-2.2
4/20 08:10	25.0	↓-2.0
4/20 08:20	23.3	↓-1.7
4/20 08:30	21.9	↓-1.4
4/20 08:40	20.8	↓-1.1
4/20 08:50	20.0	↓-0.8
4/20 09:00	19.5	↓-0.5
4/20 09:10	19.3	↓-0.2	干潮
4/20 09:20	19.5	↑0.2
4/20 09:30	19.9	↑0.4
4/20 09:40	20.8	↑0.9
4/20 09:50	21.9	↑1.1
4/20 10:00	23.4	↑1.5
4/20 10:10	25.1	↑1.7
4/20 10:20	27.2	↑2.1
4/20 10:30	29.6	↑2.4
4/20 10:40	32.2	↑2.6
4/20 10:50	35.1	↑2.9
4/20 11:00	38.2	↑3.1
4/20 11:10	41.5	↑3.3
4/20 11:20	45.0	↑3.5
4/20 11:30	48.7	↑3.7
4/20 11:40	52.4	↑3.7
4/20 11:50	56.2	↑3.8
4/20 12:00	60.1	↑3.9
4/20 12:10	64.1	↑4.0	最大潮位差
4/20 12:20	68.0	↑3.9
4/20 12:30	71.9	↑3.9
4/20 12:40	75.7	↑3.8
4/20 12:50	79.5	↑3.8
4/20 13:00	83.1	↑3.6
4/20 13:10	86.7	↑3.6
4/20 13:20	90.0	↑3.3
4/20 13:30	93.3	↑3.3
4/20 13:40	96.3	↑3.0
4/20 13:50	99.1	↑2.8
4/20 14:00	101.8	↑2.7
4/20 14:10	104.2	↑2.4
4/20 14:20	106.4	↑2.2
4/20 14:30	108.3	↑1.9
4/20 14:40	110.0	↑1.7
4/20 14:50	111.4	↑1.4
4/20 15:00	112.6	↑1.2
4/20 15:10	113.4	↑0.8
4/20 15:20	114.0	↑0.6
4/20 15:30	114.3	↑0.3	満潮
4/20 15:40	114.3	0
4/20 15:50	114.0	↓-0.3
4/20 16:00	113.4	↓-0.6
4/20 16:10	112.5	↓-0.9
4/20 16:20	111.3	↓-1.2
4/20 16:30	109.9	↓-1.4
4/20 16:40	108.2	↓-1.7
4/20 16:50	106.3	↓-1.9
4/20 17:00	104.1	↓-2.2
4/20 17:10	101.7	↓-2.4
4/20 17:20	99.2	↓-2.5
4/20 17:30	96.5	↓-2.7
4/20 17:40	93.7	↓-2.8
4/20 17:50	90.8	↓-2.9
4/20 18:00	87.8	↓-3.0
4/20 18:10	84.8	↓-3.0
4/20 18:20	81.7	↓-3.1
4/20 18:30	78.7	↓-3.0
4/20 18:40	75.7	↓-3.0
4/20 18:50	72.8	↓-2.9
4/20 19:00	70.0	↓-2.8
4/20 19:10	67.3	↓-2.7
4/20 19:20	64.7	↓-2.6
4/20 19:30	62.2	↓-2.5
4/20 19:40	60.0	↓-2.2
4/20 19:50	57.9	↓-2.1
4/20 20:00	55.9	↓-2.0
4/20 20:10	54.2	↓-1.7
4/20 20:20	52.7	↓-1.5
4/20 20:30	51.4	↓-1.3
4/20 20:40	50.3	↓-1.1
4/20 20:50	49.5	↓-0.8
4/20 21:00	48.9	↓-0.6
4/20 21:10	48.5	↓-0.4	干潮
4/20 21:20	48.4	↓-0.1
4/20 21:30	48.6	↑0.2
4/20 21:40	49.0	↑0.4
4/20 21:50	49.7	↑0.7
4/20 22:00	50.7	↑1.0
4/20 22:10	51.9	↑1.2
4/20 22:20	53.4	↑1.5
4/20 22:30	55.2	↑1.8
4/20 22:40	57.2	↑2.0
4/20 22:50	59.4	↑2.2
4/20 23:00	61.8	↑2.4
4/20 23:10	64.4	↑2.6
4/20 23:20	67.2	↑2.8
4/20 23:30	70.2	↑3.0
4/20 23:40	73.2	↑3.0
4/20 23:50	76.4	↑3.2